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Mathematics

An employer wants to compare the commute times of 1st- and 2nd-shift employees. The two histograms show the average commute times for each group. The first bar includes average commute times greater than or equal to zero and less than 6. The second bar includes average commute times greater than or equal to 6 and less than 12, and so on. Both shifts have a mean commute of 17 minutes. Which of the following statements best compares the standard deviations of the average commute times of the shifts?

A.The standard deviations are equal.
B.The standard deviation for the 1st-shift employees is greater.
C.The standard deviation for the 2nd-shift employees is greater.
D.These histograms do not provide enough information to compare the two standard deviations.

答案和解析

答案：C

解析：

Option C is correct. The data for the 2nd shift are more spread out from the mean than the data for the 1st shift.