In: Statistics and Probability
With individual lines at its various windows, a post office finds that the standard deviation for waiting times for customers on Friday afternoon is 7.2 minutes. The post office experiments with a single, main waiting line and finds that for a random sample of 27 customers, the waiting times for customers have a standard deviation of 4.35 minutes on a Friday afternoon. What is the Test Statistics to test the claim that a single line causes lower variation among waiting times for customers?
Let denotes the true standard deviation for waiting times for customers on Friday afternoon.
There is sufficient evidence to support the claim that a single line causes lower variation among waiting times for customers.