Question

A grocery store wants to track how long it takes its customers to checkout and leave with their purchases. The store plans to time 42 randomly selected customers as they move through the checkout process. If the true mean time to checkout is 6.5 minutes and the standard deviation is 2.6 minutes, what is the standard error of the mean?

Minutes=

Answer 1

The standard error of the mean (SEM) is calculated using the formula:

SEM=n​σ​

where:

σ is the standard deviation of the population,

n is the size of the sample.

Given that the standard deviation σ is 2.6 minutes and the sample size n is 42, we can substitute these values into the formula to calculate the SEM.

Explanation: