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.With a .95 probability, the sample mean will provide a margin of error of

A) 1.96.
B) .10.
C) .196.
D) 1.64.