If the Age Distribution of Customers at a Major Retail

Multiple Choice

If the age distribution of customers at a major retail chain is thought to be bell-shaped with a mean equal to 43 years and a standard deviation equal to 7 years, the percentage of customers between the ages of 29 and 57 years is:

A) approximately 81.5.
B) approximately 68.
C) at least 75.
D) approximately 95.