A random sample of 160 commercial customers of PayMor Lumber revealed that 32 had paid their accounts within a month of billing. Can normality be assumed for the sample proportion?
A)Yes.
B)No.
C)Need more information to say.

Question

Quizplus · Accepted Answer

In this case, we can use the normal distribution to approximate the sampling distribution of the sample proportion because the sample size is large enough (n=160) and the expected number of successes and failures (32 and 128, respectively) are both greater than 10. Therefore, normality can be assumed for the sample proportion.

A Random Sample of 160 Commercial Customers of PayMor Lumber