The Manager of a Grocery Store Has Taken a Random

Multiple Choice

The manager of a grocery store has taken a random sample of 100 customers.The average length of time it took these 100 customers to check out was 3 minutes.It is known that the standard deviation of the population of checkout times is 1 minute.The 95% confidence interval for the true average checkout time (in minutes) is

A) 2.5 to 3.5.
B) 1.36 to 4.64.
C) 1 to 5.
D) 2.804 to 3.196.