Probability and Statistics

59 soru

Soru 1Soru →

A mechanic serviced the following number of vehicles over a five-day period: 1010, 1515, 44, 1111, and 55.

What is the median number of vehicles serviced during this period?

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Cevap: 1010

Cevap

The median number of vehicles serviced is 1010.
To find the median, the values must first be ordered from least to greatest: 44, 55, 1010, 1111, 1515. The median is the middle number in this ordered list, which is 1010.

Adım Adım Çözüm

1
Arrange the numbers in ascending order.
44, 55, 1010, 1111, 1515
The median requires the data set to be sorted from least to greatest.
2
Identify the middle value in the sorted list.
The middle value is 1010.
Since there is an odd number of values in the list (five days), the median is exactly the middle number.

Anahtar Kavram

Measures of Central Tendency (Median)
Soru 2Soru →

During a land navigation exercise, an instructor maps out 150 possible waypoint coordinates. Of these waypoints, 45 are located in dense forest, 35 are in open terrain, 50 are near water features, and the remaining waypoints are on elevated ridges. If a cadet is randomly assigned one waypoint coordinate, what is the probability that it is located on an elevated ridge? (Express your answer as a simplified fraction)

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Cevap: 2/15; 2 / 15

Cevap

2/15
The correct probability is found by dividing the number of ridge waypoints (20) by the total number of waypoints (150). Simplifying the fraction 20/150 yields 2/15.

Adım Adım Çözüm

1
Determine the total number of possible outcomes.
Total waypoints = 150.
The denominator for a single event probability calculation is the total number of items in the set.
2
Calculate the number of favorable outcomes (elevated ridge waypoints).
150 - (45 + 35 + 50) = 150 - 130 = 20 waypoints on elevated ridges.
You must subtract the sum of all known waypoint categories from the total to find the unknown remainder.
3
Set up the probability ratio and simplify the fraction.
20 / 150 simplifies to 2 / 15.
Probability is the number of favorable outcomes divided by total outcomes. ASVAB format requires fractions to be reduced to their lowest terms.

Anahtar Kavram

Single Event Probability
Soru 3Soru →

An aviation squadron has a total of 3030 crew members available for assignment. The squadron consists of 1212 pilots, 1010 mechanics, 55 medics, and 33 navigators. If one crew member is randomly selected to lead a safety briefing, what is the probability that the selected member is NOT a mechanic?

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Cevap: 23\frac{2}{3}

Cevap

The correct probability is 23\frac{2}{3}.
The correct answer is found by identifying the total number of crew members who are not mechanics (30−10=2030 - 10 = 20) and dividing this by the total number of crew members (3030). This forms the fraction 2030\frac{20}{30}, which simplifies to 23\frac{2}{3}.

Adım Adım Çözüm

1
Identify the total number of possible outcomes.
Total crew members = 3030.
The denominator for a single event probability is the total population from which the selection is made.
2
Determine the number of favorable outcomes (crew members who are NOT mechanics).
30−10=2030 - 10 = 20 crew members.
The probability of a complementary event ('NOT' an event) can be found by subtracting the specific group from the total.
3
Calculate the probability as a ratio and simplify the fraction.
Probability = 2030=23\frac{20}{30} = \frac{2}{3}.
Probability is the number of favorable outcomes over the total outcomes, expressed in its simplest form.

Anahtar Kavram

Probability of a Complementary Event
Soru 4Soru →

A quality control inspector records the weight variations, in ounces, of five identical manufactured parts. The recorded weights are: 8.58.5, 4.04.0, 10.510.5, 6.06.0, and 7.57.5. What is the range of these recorded weights?

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Cevap: 6.5

Cevap

6.5
The range of a data set is calculated by subtracting the lowest value from the highest value. In this list, the highest weight is 10.510.5 and the lowest weight is 4.04.0. Subtracting 4.04.0 from 10.510.5 yields a range of 6.56.5.

Adım Adım Çözüm

1
Identify the maximum and minimum values in the given data set.
The maximum weight is 10.510.5 and the minimum weight is 4.04.0.
The range is defined as the difference between the highest and lowest values in a set of data.
2
Subtract the minimum value from the maximum value.
10.5−4.0=6.510.5 - 4.0 = 6.5
Performing the subtraction gives the statistical range of the data.

Anahtar Kavram

Measures of Dispersion
Soru 5Soru →

An armory has a total of 5050 training rifles on a rack. Exactly 1515 of these rifles are equipped with laser sights. If a recruit is randomly issued one of these training rifles, what is the probability, expressed as a decimal, that they receive a rifle with a laser sight?

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Cevap: 0.3

Cevap

0.3
The probability of a single event is calculated by dividing the number of specific desired outcomes by the total number of possible outcomes. In this scenario, there are 15 rifles with laser sights out of a total of 50 rifles in the armory. Therefore, the probability is 15/50. To express this as a decimal, you can simplify the fraction by dividing the numerator and denominator by 5 to get 3/10, which easily converts to 0.3.

Adım Adım Çözüm

1
Determine the total number of possible outcomes.
50
This is the total number of training rifles available on the rack.
2
Determine the number of favorable outcomes.
15
This is the number of training rifles equipped with laser sights, which represents the target event.
3
Calculate the probability by dividing the favorable outcomes by the total possible outcomes.
15 / 50 = 3 / 10 = 0.3
The basic formula for single event probability is the ratio of target outcomes to total outcomes.

Anahtar Kavram

Single Event Probability
Soru 6Soru →

A deck of flashcards used for language training contains 5050 cards. There are 1515 vocabulary cards, 2525 grammar cards, and 1010 phrase cards. If a student randomly selects one card from the deck to study, what is the probability that it is a vocabulary card?

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Cevap: 310\frac{3}{10}

Cevap

310\frac{3}{10}
The correct answer is found by dividing the number of vocabulary cards by the total number of cards in the deck. There are 1515 vocabulary cards out of 5050 total cards. The fraction 1550\frac{15}{50} simplifies to 310\frac{3}{10} when both the numerator and denominator are divided by their greatest common factor, 55.

Adım Adım Çözüm

1
Identify the total number of possible outcomes.
Total cards = 5050
The denominator of a probability fraction is the total number of items in the set.
2
Identify the number of favorable outcomes.
Vocabulary cards = 1515
The question asks specifically for the probability of drawing a vocabulary card.
3
Set up the probability fraction and simplify.
1550=310\frac{15}{50} = \frac{3}{10}
Probability is the ratio of favorable outcomes to total outcomes, and fractions should be reduced to their simplest form.

Anahtar Kavram

Calculating single event probability as the ratio of favorable outcomes to the total number of possible outcomes.
Soru 7Soru →

Match each statistical request with its correct numerical value based on the provided data sets.

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Öğeler

The mode of the set: 2,4,4,6,92, 4, 4, 6, 9
The median of the ordered set: 1,3,5,10,151, 3, 5, 10, 15
The mean of the set: 2,6,102, 6, 10
The median of the ordered set: 3,5,9,113, 5, 9, 11

Eşleşmeler

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Cevap

Mode of 2, 4, 4, 6, 9 is 4. Median of 1, 3, 5, 10, 15 is 5. Mean of 2, 6, 10 is 6. Median of 3, 5, 9, 11 is 7.
Each statistical request is paired with its exact calculated value. The mode identifies the most common value, the median finds the central value of an ordered list (averaging the middle two if the count is even), and the mean calculates the mathematical average.

Adım Adım Çözüm

1
Calculate the mode for the first set: 2,4,4,6,92, 4, 4, 6, 9
The mode is 44.
The number 44 is the only value that appears more than once, making it the most frequent value.
2
Determine the median for the second set: 1,3,5,10,151, 3, 5, 10, 15
The median is 55.
Since the list is ordered and has an odd number of elements (55), the middle value is the third element.
3
Calculate the mean for the third set: 2,6,102, 6, 10
The mean is 66.
Add the numbers (2+6+10=182 + 6 + 10 = 18) and divide by the total count (33). 18÷3=618 \div 3 = 6.
4
Determine the median for the fourth set: 3,5,9,113, 5, 9, 11
The median is 77.
Since the list has an even number of elements (44), find the average of the two middle numbers (55 and 99). 5+92=142=7\frac{5 + 9}{2} = \frac{14}{2} = 7.

Anahtar Kavram

Measures of Central Tendency
Soru 8Soru →

A student recorded the number of books they read each month over a five-month period: 1212, 77, 1919, 44, and 1313. What is the median number of books read per month?

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Cevap: 12

Cevap

12
The median is the middle value of an ordered dataset. When the numbers are ordered from least to greatest (4,7,12,13,194, 7, 12, 13, 19), the middle value is 1212.

Adım Adım Çözüm

1
Sort the data set in ascending order.
4,7,12,13,194, 7, 12, 13, 19
The median must be found from a properly ordered list of numbers.
2
Identify the middle number in the sorted list.
The 3rd number is 1212.
Since there are 55 numbers (an odd amount), the median is exactly the middle value.

Anahtar Kavram

Median
Tahmini Süre:45s
Soru 9Soru →

A logistics manager is tracking the number of supply crates shipped each week. Over the first four weeks of a five-week period, the facility shipped 1313, 2727, 1818, and 2626 crates. How many crates must be shipped in the fifth week to achieve an average (mean) of 2424 crates per week for the entire five-week period?

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Cevap: 3636

Cevap

The facility must ship 3636 crates in the fifth week.
To find a missing value when the mean is known, first determine the total sum required. An average of 24 over 5 weeks means the total crates shipped must equal 120 (24 × 5). Since 84 crates were shipped in the first four weeks (13 + 27 + 18 + 26), 36 more crates are needed in the final week (120 - 84) to meet the goal.

Adım Adım Çözüm

1
Calculate the total number of crates needed for all 55 weeks.
24×5=12024 \times 5 = 120
The mean formula is (total sum) ÷ (number of values). Therefore, the required total sum is the target mean multiplied by the total number of weeks.
2
Calculate the sum of the crates shipped in the first 44 weeks.
13+27+18+26=8413 + 27 + 18 + 26 = 84
This determines how many crates have already been accounted for in the total.
3
Subtract the sum of the first 44 weeks from the target total to find the missing value.
120−84=36120 - 84 = 36
The difference between the required total and the current total is the value needed for the final week.

Anahtar Kavram

Solving for a Missing Data Point Given the Mean
Soru 10Soru →

A logistics officer is analyzing the fuel consumption of five transport trucks. The data for the first four trucks is 4545, 5252, 4848, and 5555 gallons. The fuel data for the fifth truck was lost, but the officer remembers that it consumed more fuel than any of the other four trucks. If the mean fuel consumption of all five trucks is exactly equal to their median, how many gallons of fuel did the fifth truck consume?

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Cevap: 6060

Cevap

The fifth truck consumed 6060 gallons of fuel.
Since the fifth truck consumed more fuel than the other four, the sorted order of the five values is 4545, 4848, 5252, 5555, and xx. The median of these five values is the third value, which is 5252. The problem states that the mean equals the median, so the equation is (45+48+52+55+x)/5=52(45 + 48 + 52 + 55 + x) / 5 = 52. Simplifying the numerator gives (200+x)/5=52(200 + x) / 5 = 52. Multiplying both sides by 55 results in 200+x=260200 + x = 260. Subtracting 200200 from both sides gives x=60x = 60.

Adım Adım Çözüm

1
Determine the median of the five values.
The median is 5252.
Since the fifth truck consumed the most fuel, let its consumption be xx. The sorted order of the five trucks is 4545, 4848, 5252, 5555, xx. The median of five ordered values is the third value.
2
Set up an equation for the mean.
Mean = (200+x)/5(200 + x) / 5
The mean is the sum of all five values (45+48+52+55+x=200+x45 + 48 + 52 + 55 + x = 200 + x) divided by the total number of trucks (55).
3
Equate the mean and the median to solve for xx.
(200+x)/5=52(200 + x) / 5 = 52
The problem states that the mean fuel consumption is exactly equal to the median.
4
Solve the algebraic equation.
x=60x = 60
Multiplying both sides by 55 gives 200+x=260200 + x = 260. Subtracting 200200 from both sides gives x=60x = 60.

Anahtar Kavram

Solving for an unknown data point by equating the mean and the median of an ordered dataset.
Soru 11Soru →

A logistics specialist is inventorying six shipping crates. The median weight of the crates is 4545 pounds, and the mode is 4040 pounds. The weights of five of the crates are 5050, 4040, 5555, 4242, and 4040 pounds. What is the weight of the sixth crate?

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Cevap: 48

Cevap

The weight of the sixth crate is 4848 pounds.
The correct answer is 4848. To find the missing weight, first arrange the known weights in ascending order: 4040, 4040, 4242, 5050, 5555. Since there are 66 crates in total, the median is the average of the 3rd and 4th values. Based on the known numbers, the 3rd value must be 4242 and the 4th value must be the unknown weight, xx (if xx were smaller or larger, the middle values would average to 4141 or 4646, not 4545). Setting up the equation: 42+x2=45\frac{42 + x}{2} = 45. Multiplying both sides by 22 gives 42+x=9042 + x = 90. Subtracting 4242 from both sides yields x=48x = 48. Adding 4848 to the set also ensures 4040 remains the mode.

Adım Adım Çözüm

1
Sort the known weights in ascending order.
4040, 4040, 4242, 5050, 5555
The median depends on the ordered numerical position of values in a data set.
2
Identify how the median is calculated for 66 items.
The median is the average of the 3rd and 4th items.
Because there is an even number of crates (66), there is no single middle value. The median is the mean of the two central numbers.
3
Determine the position of the missing value, xx.
The 3rd item must be 4242, and the 4th item must be xx.
If xx were smaller than 4242, the middle two numbers would be 4040 and 4242 (median 4141). If xx were 5050 or larger, the middle two numbers would be 4242 and 5050 (median 4646). To get a median of 4545, xx must be the 4th value.
4
Set up an equation for the median and solve for xx.
42+x2=45⇒42+x=90⇒x=48\frac{42 + x}{2} = 45 \Rightarrow 42 + x = 90 \Rightarrow x = 48
The average of the 3rd (4242) and 4th (xx) numbers must equal the given median (4545).
5
Verify that the mode remains 4040.
The final set is 4040, 4040, 4242, 4848, 5050, 5555. The number 4040 appears twice and is the most frequent.
Ensures all conditions stated in the problem are met.

Anahtar Kavram

Measures of Central Tendency (Median of an even-numbered data set)

Alternatif Yöntem

You can logically deduce the answer without full algebra: The median is exactly halfway between the two middle numbers. Since the median is 4545 and the lower middle number is 4242 (a distance of 33), the upper middle number must be exactly 33 units above 4545, which is 4848.
Tahmini Süre:2m 0s
Soru 12Soru →

Review the four distinct practical situations below. Pair each descriptive problem with its mathematically correct calculated result.

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Öğeler

A baker used 44, 88, 1111, and 1313 cups of sugar over four days. Determine the mean daily usage.
A delivery driver logged 55, 1212, 77, 1414, 99, and 1111 miles on six different routes. Find the median distance.
A retail shop sold hats in sizes 88, 66, 88, 1212, 66, 88, and 1515. Identify the mode.
A student earned scores of 66 and 1010 on two assignments. Find the score needed on the third assignment to achieve a mean of 99.

Eşleşmeler

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Cevap

The correct matches are: Mean usage is 99, median distance is 1010, mode size is 88, and the required assignment score is 1111.
Each statistical measure is calculated according to its definition: the mean is the sum divided by the count, the median is the middle value of an ordered list (or average of two middle values), the mode is the most frequent value, and a missing value can be found algebraically using the mean formula.

Adım Adım Çözüm

1
Determine the mean for the baker's sugar usage.
The sum is 3636, divided by 44 equals 99.
The arithmetic mean requires dividing the sum of all values by the total count of values.
2
Determine the median for the delivery driver's distances.
The sorted list is 5,7,9,11,12,145, 7, 9, 11, 12, 14. The average of the middle two values is (9+11)÷2=10(9 + 11) \div 2 = 10.
For an even number of data points, the median is the average of the two middle numbers in an ordered list.
3
Determine the mode for the hat sizes.
The mode is 88.
The mode is the value that appears most often in a dataset.
4
Calculate the missing assignment score.
The required score is 1111.
Using the algebraic formula for mean: (6+10+x)÷3=9(6 + 10 + x) \div 3 = 9, which simplifies to 16+x=2716 + x = 27.

Anahtar Kavram

Measures of central tendency (mean, median, mode) and using algebraic substitution to find a missing data point given a target mean.
Soru 13Soru →

Match each statistical scenario with its corresponding numerical value based on the principles of central tendency.

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Öğeler

The median of the sequence 2x−12x-1, 2x+32x+3, 2x2x, 2x+52x+5, and 2x−42x-4, given x=6x=6.
The score required on a 6th assessment to raise an existing 5-assessment mean of 7474 to a new mean of 7676.
The arithmetic mean of the modes in the data set: 14,18,14,22,19,22,25,2114, 18, 14, 22, 19, 22, 25, 21.
The absolute difference between the mean and the median of the data set: 2,8,10,15,202, 8, 10, 15, 20.

Eşleşmeler

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Cevap

The algebraic sequence median is 12, the required 6th assessment score is 86, the mean of the modes is 18, and the difference between the mean and median is 1.
Each statistical scenario is solved by accurately applying the definitions and formulas for mean, median, and mode, as detailed in the matching explanations.

Adım Adım Çözüm

1
Calculate the median of the algebraic sequence by substituting x=6 and sorting the results.
The substituted values are 11, 15, 12, 17, and 8. Sorted, they are 8, 11, 12, 15, 17. The median is 12.
The median requires evaluating the expressions first, then sorting the data set from least to greatest to find the positional center.
2
Calculate the required 6th assessment score using the mean formula.
Target sum = 6 × 76 = 456. Current sum = 5 × 74 = 370. Required score = 456 - 370 = 86.
The mean is the total sum divided by the number of values. Manipulating this formula allows isolation of the missing value.
3
Identify the modes of the bimodal set and average them.
The modes are 14 and 22. Their mean is (14 + 22) / 2 = 18.
The mode is the most frequent value. This set has two modes. Their average is found by adding them and dividing by 2.
4
Find the absolute difference between the mean and median of the final set.
Sum = 55, Mean = 55 / 5 = 11. Median = 10. Difference = |11 - 10| = 1.
Comparing multiple measures of central tendency requires calculating each independently before finding their difference.

Anahtar Kavram

Measures of Central Tendency
Soru 14Soru →

A naval navigation team is evaluating different telemetry datasets. Match each statistical description to its correct calculated value.

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Öğeler

The median of the unsorted frequency readings (in GHz): 1111, 44, 1515, 77, 1818, and 99.
The required fifth reading to achieve a target mean of 1818 dB, given previous readings of 1414, 1616, 2020, and 1818.
The new mean if an outlier of 3434 is added to a dataset of 55 previous readings whose sum is 5050.
The mode of the recorded pulse widths (in ms): 2222, 1515, 1515, 2222, 1010, 1515, and 2828.

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The median is 10, the missing fifth reading is 22, the new mean is 14, and the mode is 15.
Each correct match applies the fundamental operations for finding the median of an even set, determining a missing value from a given mean, calculating a shifted mean, and identifying the mode.

Adım Adım Çözüm

1
Calculate the median of the frequency readings.
Sorted order: 4,7,9,11,15,184, 7, 9, 11, 15, 18. Median is 1010.
The median of an even-numbered dataset is the average of the two middle values after sorting.
2
Calculate the missing fifth reading.
Total required = 9090. Existing sum = 6868. Missing value = 2222.
To find a missing value for a target mean, multiply the target mean by the total number of items, then subtract the sum of existing items.
3
Calculate the new mean after adding an outlier.
New sum = 8484, new item count = 66. New mean = 1414.
A mean shifts when a new value is introduced; both the total sum and the total count of items must be updated.
4
Identify the mode of the pulse widths.
The mode is 1515.
The mode is simply the value with the highest frequency of occurrence.

Anahtar Kavram

Measures of Central Tendency
Soru 15Soru →

A culinary instructor is reviewing the final exam scores of six students to determine the middle performance level of the class. The scores recorded are 8484, 7272, 9090, 7676, 8888, and 6464. What is the median score of this group of students?

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Cevap: 8080

Cevap

The median score is 8080.
To find the median, the values must first be arranged in numerical order: 6464, 7272, 7676, 8484, 8888, 9090. Because there are six numbers (an even amount), the median is the average of the two central numbers, 7676 and 8484. Adding them together yields 160160, and dividing by 22 gives a median of 8080.

Adım Adım Çözüm

1
Sort the given scores from least to greatest.
6464, 7272, 7676, 8484, 8888, 9090
The median is the exact middle value of an ordered dataset, making sorting the mandatory first step.
2
Identify the middle value(s) of the sorted list.
The middle two values are 7676 and 8484.
Since there is an even number of data points (66), there is no single middle value. The median position falls exactly between the 3rd and 4th values.
3
Calculate the average of the two middle values.
76+842=1602=80\frac{76 + 84}{2} = \frac{160}{2} = 80
The median of a dataset with an even number of values is the arithmetic mean of the two central values.

Anahtar Kavram

Median of a Dataset with an Even Number of Values
Tahmini Süre:1m 0s
Soru 16Soru →

A quality control inspector is reviewing a batch of 12 electronic components, of which 8 are functioning properly and 4 are defective. If the inspector randomly selects 3 components from the batch one at a time without replacement, what is the probability that exactly 2 of the selected components are functioning properly and 1 is defective?

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Cevap: 2855\frac{28}{55}

Cevap

The correct probability is 2855\frac{28}{55}.
The correct answer accounts for both the dependent nature of the events (drawing without replacement) and the multiple combinations that satisfy the condition (3 different orders).

Adım Adım Çözüm

1
Determine the probabilities of drawing 2 functioning (F) and 1 defective (D) component in one specific order, such as F, then F, then D.
P(F1)=812P(F_1) = \frac{8}{12}, P(F2)=711P(F_2) = \frac{7}{11}, and P(D3)=410P(D_3) = \frac{4}{10}.
Because the components are drawn without replacement, the total pool (denominator) and the pool of available specific components (numerator) decrease with each successful draw.
2
Calculate the joint probability of this specific sequence by multiplying the individual probabilities.
812×711×410=23×711×25=28165\frac{8}{12} \times \frac{7}{11} \times \frac{4}{10} = \frac{2}{3} \times \frac{7}{11} \times \frac{2}{5} = \frac{28}{165}.
The probability of a sequence of dependent events occurring together is the product of their conditional probabilities.
3
Identify how many different sequences can result in exactly 2 functioning and 1 defective component.
There are 3 possible sequences: F-F-D, F-D-F, and D-F-F.
The single defective component can be the first, second, or third one drawn.
4
Calculate the total probability of achieving this outcome by multiplying the probability of a single sequence by the number of possible sequences.
3×28165=841653 \times \frac{28}{165} = \frac{84}{165}.
Each of the 3 valid sequences is mutually exclusive and has the exact same probability of occurring, so we can sum their probabilities (or multiply by 3).
5
Simplify the final fraction.
84165\frac{84}{165} simplifies to 2855\frac{28}{55} by dividing the numerator and denominator by 3.
Fractions should always be presented in their simplest form.

Anahtar Kavram

Compound Probability of Dependent Events with Permutations
Soru 17Soru →

A maintenance chief is reviewing the repair times (in hours) for five generators: 88, 1212, 1515, 99, and 1616. A sixth generator's repair time is added to the records. If the median repair time for all six generators is exactly 11.511.5 hours, what is the repair time of the sixth generator?

Cevabı ve açıklamayı göster

Cevap: 1111

Cevap

The repair time of the sixth generator is 1111 hours.
The correct answer is found by first sorting the existing times into ascending order: 8,9,12,15,168, 9, 12, 15, 16. Because there will be six total items, the median is calculated by averaging the 3rd and 4th values. The 3rd value is 1212, and the target median is given as 11.511.5. This sets up the equation (12+x)/2=11.5(12 + x) / 2 = 11.5. Multiplying both sides by 22 gives 12+x=2312 + x = 23. Subtracting 1212 from both sides reveals the 6th generator's time must be 1111 hours.

Adım Adım Çözüm

1
Sort the known repair times in ascending order.
8,9,12,15,168, 9, 12, 15, 16
The median depends on the ordered sequence of data, not the order in which it was recorded.
2
Determine how the median is calculated for a six-item data set.
The median will be the average of the 3rd and 4th values in the sorted list.
For an even number of data points, the median is exactly halfway between the two central numbers.
3
Set up an equation using the known middle value and the target median.
The current 3rd value is 1212. The 4th value will be the new time xx. Equation: 12+x2=11.5\frac{12 + x}{2} = 11.5
We know the final median must be 11.511.5, and 1212 is the existing middle value that must be paired with xx to achieve this average.
4
Solve the equation for xx.
12+x=2312 + x = 23, which simplifies to x=11x = 11.
Multiplying both sides by 22 and then subtracting 1212 isolates the unknown variable.

Anahtar Kavram

Measures of Central Tendency
Soru 18Soru →

A cybersecurity analyst is monitoring the number of unauthorized access attempts blocked by a firewall each day. The mean number of blocked attempts for the entire 55-day work week is exactly 3232. If the daily counts from Monday to Thursday were 2828, 3535, 2727, and 3434, how many access attempts were blocked on Friday?

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Cevap: 36

Cevap

The firewall blocked 36 access attempts on Friday.
The correct answer is found by determining the total sum required to achieve the target mean for 55 days (32×5=16032 \times 5 = 160), and then subtracting the sum of the four known days (124124) from that total. This yields a required value of 3636 for the final day.

Adım Adım Çözüm

1
Calculate the total sum of access attempts required for all 55 days.
32×5=16032 \times 5 = 160
The mean is equal to the total sum divided by the number of values. Therefore, the total sum is the mean multiplied by the number of values (NN).
2
Calculate the sum of the known access attempts from the first four days.
28+35+27+34=12428 + 35 + 27 + 34 = 124
We must determine the combined total of the known days before we can find the missing day's value.
3
Subtract the sum of the four days from the required 55-day total to find Friday's count.
160−124=36160 - 124 = 36
The difference between the overall required total and the sum of the known values represents the exact value needed for the final day.

Anahtar Kavram

Calculating a missing value from a data set when given the arithmetic mean and the remaining values.
Soru 19Soru →

A medical detachment is tracking a patient's resting heart rate over a six-day period. The mean heart rate over the six days is 6969 beats per minute (bpm). The readings for five of those days are 6666, 7272, 6868, 7878, and 6565. What is the median heart rate for the entire six-day period?

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Cevap: 67

Cevap

67
The correct answer is derived in two phases. First, the missing sixth value is found by subtracting the sum of the five known values (349) from the total sum of all six values (69 * 6 = 414), which yields 65. Second, all six values are sorted from least to greatest: 65, 65, 66, 68, 72, 78. Since there are 6 values, the median is the exact average of the two middle numbers (66 and 68). (66 + 68) / 2 = 67 bpm.

Adım Adım Çözüm

1
Calculate the total sum of the heart rates for all six days.
414414
The total sum is required to find the value of the missing sixth day. Multiply the given mean (6969) by the total number of days (66).
2
Calculate the sum of the five known heart rates.
349349
Adding the given values (66+72+68+78+6566 + 72 + 68 + 78 + 65) allows us to see how much of the total sum is accounted for.
3
Determine the heart rate for the sixth day.
6565
Subtracting the sum of the known days (349349) from the total sum (414414) reveals the missing data point.
4
Arrange all six heart rates in ascending order.
65,65,66,68,72,7865, 65, 66, 68, 72, 78
The median is a measure of position, which strictly requires the entire dataset to be ordered from least to greatest.
5
Identify the two middle values and calculate their average.
6767
Because there is an even number of values (n=6n=6), the median is the mean of the 3rd and 4th values: (66+68)/2(66 + 68) / 2.

Anahtar Kavram

Solving for a missing data value using the arithmetic mean, followed by determining the median of an even-numbered dataset.
Soru 20Soru →

An environmental scientist measures the daily water flow (in gallons per minute) from a natural spring over five days. The recorded values are 2222, 1818, 2525, 2020, and 1717. If the scientist needs the average (mean) flow rate across a full six-day period to be exactly 2121 gallons per minute, what must the flow rate be on the sixth day?

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Cevap: 2424

Cevap

2424
To find the missing value for the sixth day, first determine the total sum required for all six days. Since the target mean is 2121, the required total sum is 21×6=12621 \times 6 = 126. Next, find the sum of the five days already recorded: 22+18+25+20+17=10222 + 18 + 25 + 20 + 17 = 102. The required flow rate for the sixth day is the difference between these two sums: 126−102=24126 - 102 = 24.

Adım Adım Çözüm

1
Calculate the sum of the water flow for the first five days.
22+18+25+20+17=10222 + 18 + 25 + 20 + 17 = 102
This establishes how much total water flow has already been recorded.
2
Calculate the required total sum for the full six days to achieve the target mean.
21×6=12621 \times 6 = 126
The formula for the mean is Total Sum divided by the Number of Values. Therefore, Total Sum = Mean × Number of Values.
3
Subtract the sum of the first five days from the target total sum.
126−102=24126 - 102 = 24
The difference between the target six-day total and the current five-day total gives the required value for the sixth day.

Anahtar Kavram

Calculating a missing data point in a set when the target arithmetic mean is provided.
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