Question

A sample standard deviation of $15$minutes is the same as a sample variance of __________ minutes.

Short answer

A sample standard deviation of$15$ minutes is the sample as the sample variance of $0.258$ minutes.

Step-by-step solution

Given information

Given in the question that, Suppose an airline claims that its flights are consistently on time with an average delay of at most $15$minutes. It claims that the average delay is so consistent that the variance is no more than $150$minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next $25$flights. The average delay for those $25$flights is $22$minutes with a standard deviation of$15$minutes.

Explanation 

A sample standard deviation is a square root of variance. Therefore:

$15=\sqrt{V}$

$V=0.258$

Therefore, a sample standard deviation of$15$minutes is the sample as the sample variance of $0.258$minutes.