On average, it takes a shoe factory 21 minutes, with a standard deviation of 3 minutes, to manufacture a pair of running shoes. How often will it take the factory more than 27 minutes to manufacture a pair of running shoes? Note: assume that a normal model is appropriate for the distribution of manufacturing times.
a. It takes the factory more than 27 minutes to manufacture a pair of running shoes about 2.5 of the time.
b. It takes the factory more than 27 minutes to manufacture a pair of running shoes about 47.5 of the time.
c. It takes the factory more than 27 minutes to manufacture a pair of running shoes about 95 of the time.
d. It takes the factory more than 27 minutes to manufacture a pair of running shoes about 5 of the time.