00:01
We have a population of size 15 ,000.
00:05
We have a sample of 200, and the proportion for this population is 0 .6.
00:19
And for part a, we want the sampling distribution of p -hat.
00:24
Well, that is going to be approximately normal, since n is less than or equal to 0 .05, so 5 % of the population.
00:39
And n times p is times 1 minus p is equal to 200 times 0 .6 times 0 .4, which is 120 times 0 .4 is 48, so that is greater than 10.
01:00
So our conditions are met, approximately normal because that n is greater than or equal to 10.
01:11
Okay, so answer a.
01:17
And then for part b, determine the mean of the sampling distribution for p -hat.
01:23
Well, p -hat will be approximately normal with a mean for p -hat equal to p, which is 0 .6.
01:37
And the standard deviation for p -hat will be the square root of p times 1 minus p over n...