A lightbulb manufacturing plant's production line has determined that the probability a lightbulb will be defective is 0.04. The quality control team decides to take a random sample of 500 lightbulbs and measure the proportion of those lightbulbs that are defective.
-Can we apply the normal approximation to the distribution of the sample proportion of defective lightbulbs?
A) No, because there is only one sample.
B) No, because 0.04 is less than 0.10.
C) Yes, because 0.04500 and 0.96500 are both greater than 10.
D) Yes, because it is a random sample.

Question

Quizplus · Accepted Answer

The normal approximation can be applied if np and n(1-p) are both greater than 10. Here, np = 500 * 0.04 = 20 and n(1-p) = 500 * 0.96 = 480, both of which are greater than 10.

A Lightbulb Manufacturing Plant's Production Line Has Determined That the Probability