The Shelf Life of a Battery Produced by One Major

Multiple Choice

The shelf life of a battery produced by one major company is known to be normally distributed, with a mean life of 3.5 years and a standard deviation of 0.75 years. What percent of batteries last between 1.25 and 5.75 years?

A) 99.7%
B) 95%
C) 68%
D) 50%