00:01
In 31, it says a simple random sample of 400 individuals provide 100 yes responses.
00:07
So i have that written over here to the side.
00:09
N is 400.
00:11
X is going to represent the number of yes responses, in which case we have 100.
00:15
Part a says, what is the point estimate of the proportion of the population that would provide yes responses? so the point estimate is pretty simple in this case.
00:25
Point estimate is the number of yeses over the total.
00:30
Which is 100 over 400.
00:34
You can write that as one -fourth or as 0 .25.
00:41
In part b, we're asked, what is your estimate of the standard error of the proportion? so our standard error is going to be square root of p -hat times 1 minus p -hat.
01:01
You can also call that q -hat over n.
01:04
P hat is our point estimate.
01:06
We know that from earlier, so we have 0 .25 times 0 .75 over 400, all under the radical, and that is 0 .017...