In: Statistics and Probability
A bank has kept records of the checking balances of its
customers and determined that the population average daily balance
of its customers is $300 with a population standard deviation of
$48. A random sample of 144 checking accounts is
selected.
| a. | 
 What is the probability that the sample mean will be more than $306.60?  | 
| b. | 
 What is the probability that the sample mean will be less than $310?  | 
| c. | 
 What is the probability that the sample mean will be between $302 and $308?  |