Random samples of size 525 are taken from a process (an infinite population) whose population proportion is .3. The standard deviation of the sample proportions (i.e., the standard error of the proportion) is _____.
A) .0004
B) .2100
C) .3000
D) .0200

Question

Quizplus · Accepted Answer

The standard error of the proportion (SE) can be calculated using the formula:

SE = sqrt(p(1-p) / n)

where p is the population proportion, and n is the sample size.

In this case, p = 0.3 and n = 525. Therefore,

SE = sqrt(0.3(1-0.3) / 525)
   = sqrt(0.21 / 525)
   = 0.0200

So the standard deviation of the sample proportions is 0.0200, which corresponds to choice D.

Random Samples of Size 525 Are Taken from a Process