Question

food fryers manufactured by a company that supplies food trucks can fry a mean of 132.4 pounds of food per hour with a standard deviation of 3.9 pounds per hour. in a given hour, how much food would 99.7% of these fryers fry?
choice
a. 120.7 pounds per hour to 144.1 pounds per hour
b. 116.8 pounds per hour to 148.0 pounds per hour
c. 124.6 pounds per hour to 140.2 pounds per hour
d. 128.5 pounds per hour to 136.3 pounds per hour

Explanation:

Step1: Recall Empirical Rule

For a normal distribution, 99.7% of data lies within $ \mu \pm 3\sigma $, where $ \mu $ is mean and $ \sigma $ is standard deviation.
Here, $ \mu = 132.4 $, $ \sigma = 3.9 $.

Step2: Calculate Lower Bound

Lower bound = $ \mu - 3\sigma = 132.4 - 3\times3.9 $
$ = 132.4 - 11.7 = 120.7 $

Step3: Calculate Upper Bound

Upper bound = $ \mu + 3\sigma = 132.4 + 3\times3.9 $
$ = 132.4 + 11.7 = 144.1 $

Answer:

A. 120.7 pounds per hour to 144.1 pounds per hour