Exhibit 6-7
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 6-7. What percentage of items will weigh between 6.4 and 8.9 ounces?
A)0.1145
B)0.2881
C)0.1736
D)0.4617

Question

Quizplus · Accepted Answer

To find the percentage of items weighing between 6.4 and 8.9 ounces, we calculate the z-scores for both values and find the area between them under the standard normal distribution. The z-score for 6.4 is (6.4-8)/2 = -0.8, and for 8.9 is (8.9-8)/2 = 0.45. Using standard normal distribution tables or a calculator, the area between these z-scores corresponds to approximately 46.17% of the data.

Exhibit 6-7 The Weight of Items Produced by a Machine Is Normally