00:01
For this problem, we are asked to find a 95 % confidence interval for p, given that p hat equals 0 .38 and n equals 500.
00:09
So we can use the formula that i have shown on screen here.
00:13
I'll start off with finding the lower bound.
00:15
So we have p hat equals 0 .38.
00:18
Then we have minus.
00:19
Now our z score for the 95 % confidence is going to be 1 .96.
00:25
Let me just double check that.
00:28
So i'm getting that using stat key.
00:30
Yes, it's 1 .96.
00:32
Then we multiply that by the square root of 0 .38 times 1 minus 0 .38 divided by n, so we divide by 500.
00:46
And i need to put a star here.
00:51
All right, so that will be our lower end point.
00:53
I'll round that in a second...