A 50-Volt Battery Must Be Between 55 and 45 Volts

Multiple Choice

A 50-volt battery must be between 55 and 45 volts when it leaves the factory. Two hundred samples of batteries have yielded the following data: average charge of 49 volts with a standard deviation of 2.5 volts. What is the probability of producing an out-of-spec battery?

A) 0.06
B) 0.80
C) 0.53
D) 0.12
E) 0.32