Exhibit 6-5
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces.
-Refer to Exhibit 6-5. What percentage of items will weigh at least 11.7 ounces?
A)46.78%
B)96.78%
C)3.22%
D)53.22%

Question

Quizplus · Accepted Answer

To solve this problem, we need to find the area under the normal curve to the right of the value of 11.7 ounces. We can standardize the value of 11.7 by subtracting the mean and dividing by the standard deviation: 
z = (11.7 - 8) / 2 = 1.85

Using a standard normal distribution table or calculator, we can find that the area to the right of z = 1.85 is 0.0322, or 3.22%. Therefore, the percentage of items that will weigh at least 11.7 ounces is 3.22%.

Exhibit 6-5 The Weight of Items Produced by a Machine Is Normally