Ten experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their ratings were: 34, 35, 41, 28, 26, 29, 32, 36, 38 and 40. What is the mean deviation?
A) 8.00
B) 4.12
C) 12.67
D) 0.75

Question

Quizplus · Accepted Answer

1. Find the mean: 
    (34 + 35 + 41 + 28 + 26 + 29 + 32 + 36 + 38 + 40) / 10 = 34.9 
2. Find the absolute deviations from the mean: 
    |34 - 34.9| = 0.9 
    |35 - 34.9| = 0.1 
    |41 - 34.9| = 6.1 
    |28 - 34.9| = 6.9 
    |26 - 34.9| = 8.9 
    |29 - 34.9| = 5.9 
    |32 - 34.9| = 2.9 
    |36 - 34.9| = 1.1 
    |38 - 34.9| = 3.1 
    |40 - 34.9| = 5.1 
3. Find the average absolute deviation: 
    (0.9 + 0.1 + 6.1 + 6.9 + 8.9 + 5.9 + 2.9 + 1.1 + 3.1 + 5.1) / 10 = 4.12 
Therefore, the mean deviation is 4.12, which is closest to choice B.

Ten Experts Rated a Newly Developed Chocolate Chip Cookie on a Scale