The Actual Number of Hours That a Candle Will Burn

Multiple Choice

The actual number of hours that a candle will burn has an approximate normal distribution with a mean of 18 hours and a standard deviation of 1.2 hours. What is the probability that the candle will burn for Less than 15.6 hours? Give your answer as a percentage.

A) 2.5%
B) 5%
C) 16%
D) 95%
E) None of the above.