The Mean Amount of Gasoline and Services Charged by Key

Multiple Choice

The mean amount of gasoline and services charged by Key Refining Company credit customers is $70 per month. The distribution of amounts spent is approximately normal with a standard deviation of
$10) What is the probability of selecting a credit card customer at random and finding the customer charged between $70 and $83?

A) 0.1962
B) 0.4032
C) 0.3413
D) 0.4750
E) None of the choices are correct