The following data reflect the number of customers who return merchandise for a refund on Monday.Note these data reflect the population of all 10 Mondays for which data are available. Based on these data,what is the standard deviation?
A)13.03
B)12.36
C)39
D)152.8

Question

The following data reflect the number of customers who return merchandise for a refund on Monday.Note these data reflect the population of all 10 Mondays for which data are available.  Based on these data,what is the standard deviation?
A)13.03 
B)12.36 
C)39 
D)152.8

Quizplus · Accepted Answer

To calculate the standard deviation, we need to find the mean first. The mean of the data is (11+12+10+14+16+8+13+15+9+11)/10 = 119/10 = 11.9. Next, we need to subtract the mean from each value, square the result, and sum those squares. (11-11.9)^2 + (12-11.9)^2 + ... + (11-11.9)^2 = 142.8. Finally, divide by the sample size (n=10) and take the square root. sqrt(142.8/10) = 12.36. Therefore, the standard deviation is 12.36, and the best choice is B.

The Following Data Reflect the Number of Customers Who Return