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Zorluk: OrtaDescriptive Statistics and Data Representations

A local fitness center recorded the number of weekly workout sessions attended by a sample of 2020 members over the past month. The results are summarized in the frequency table below:

Sessions per WeekNumber of Members
1144
2266
3355
4433
5522

What is the positive difference between the mean and the median number of weekly workout sessions for these 2020 members?

  1. 0.150.15Cevap
  2. B
    0.350.35
  3. C
    0.500.50
  4. D
    0.650.65
  5. E
    8.108.10

Cevap

The positive difference between the mean and median number of weekly workout sessions is 0.150.15.
To find the mean, multiply each number of sessions by its frequency, sum the products, and divide by the total number of members (2020): (4+12+15+12+10)/20=53/20=2.65(4 + 12 + 15 + 12 + 10) / 20 = 53 / 20 = 2.65. To find the median for 2020 members, take the average of the 10th and 11th values in order. Looking at cumulative frequencies, the 5th through 10th entries are 22 and the 11th through 15th entries are 33. The median is (2+3)/2=2.5(2 + 3)/2 = 2.5. The positive difference is 2.652.5=0.152.65 - 2.5 = 0.15.

Adım Adım Çözüm

1
Calculate the total number of sessions.
(1×4)+(2×6)+(3×5)+(4×3)+(5×2)=4+12+15+12+10=53(1 \times 4) + (2 \times 6) + (3 \times 5) + (4 \times 3) + (5 \times 2) = 4 + 12 + 15 + 12 + 10 = 53
Multiply each session value by its corresponding frequency to find the total sum of sessions.
2
Calculate the mean number of sessions.
Mean=5320=2.65\text{Mean} = \frac{53}{20} = 2.65
Divide the total number of sessions by the total number of members (2020).
3
Find the median number of sessions.
\text{Median} = \frac{2 + 3}{2} = 2.5
With 2020 total data points, the median is the average of the 10th and 11th ordered values. The cumulative frequencies show that the first 44 values are 11, the next 66 values (5th through 10th) are 22, and the next 55 values (11th through 15th) are 33. The 10th value is 22 and the 11th value is 33.
4
Calculate the positive difference between the mean and median.
|2.65 - 2.5| = 0.15
Subtract the median from the mean to find the difference.

Anahtar Kavram

Calculating mean and median from a frequency table
Tahmini Süre:1m 30s
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