Customers of the Key Refining Company Charge an Average of $70

Multiple Choice

Customers of the Key Refining Company charge an average of $70 per month. The distribution of amounts charged 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