Question

Difficulty: MediumDescriptive Statistics and Data Representations

A customer satisfaction survey asked 2525 patrons at a local restaurant to rate their dining experience on a scale from 11 (poor) to 55 (excellent). The frequency table below summarizes the ratings collected:

RatingNumber of Patrons
13
25
38
46
53

What is the positive difference between the mean rating and the median rating of these 2525 patrons?

  1. 0.040.04Answer
  2. B
    0.000.00
  3. C
    1.961.96
  4. D
    12.2012.20
  5. E
    58.6058.60

Answer

The positive difference between the mean rating and the median rating is 0.040.04.
To find the positive difference, first compute the mean by calculating the sum of products of each rating and its frequency: (1×3)+(2×5)+(3×8)+(4×6)+(5×3)=76(1 \times 3) + (2 \times 5) + (3 \times 8) + (4 \times 6) + (5 \times 3) = 76. Dividing 7676 by the total number of patrons (2525) yields a mean of 3.043.04. Next, find the median by identifying the 13th13\text{th} ordered rating out of 2525. The cumulative frequency reaches 88 after rating 2 and 1616 after rating 3, so the 13th13\text{th} entry is 33. The positive difference between the mean (3.043.04) and median (3.003.00) is 0.040.04.

Step-by-Step Solution

1
Calculate the total sum of all ratings.
Sum =(1×3)+(2×5)+(3×8)+(4×6)+(5×3)=3+10+24+24+15=76= (1 \times 3) + (2 \times 5) + (3 \times 8) + (4 \times 6) + (5 \times 3) = 3 + 10 + 24 + 24 + 15 = 76.
Each rating value must be multiplied by its frequency to find the total value of all responses.
2
Calculate the mean rating.
Mean =7625=3.04= \frac{76}{25} = 3.04.
Divide the total sum of all ratings by the total number of patrons (2525).
3
Determine the median rating.
Median =3= 3.
With 2525 data points arranged in ascending order, the median is the 25+12=13th\frac{25 + 1}{2} = 13\text{th} score. Accumulating frequencies: Ratings 1 and 2 cover the first 3+5=83 + 5 = 8 scores, while Rating 3 covers the 9th9\text{th} through 16th16\text{th} scores. Thus, the 13th13\text{th} score is 33.
4
Find the positive difference between the mean and median.
Difference =3.043.00=0.04= 3.04 - 3.00 = 0.04.
Subtract the median rating (33) from the mean rating (3.043.04).

Key Concept

Calculating Mean and Median from a Frequency Table
Estimated Time:1m 30s
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