00:01
So for this problem, we are told that we have effectively a sample proportion p -hat of 108 divided by 150.
00:13
So that looked like a 6.
00:15
It's 108 over 150.
00:17
So i'll just crunch those numbers on screen.
00:19
108 over 150 equals 0 .72.
00:22
So we have a sample proportion of 0 .72.
00:25
Our confidence interval is going to be given in the form of p hat plus or minus z for a proportion of, let's see here.
00:36
We're looking at a 90 % confidence interval.
00:39
So this is going to be z for a left proportion of 0 .05, or the absolute value really of the z times our, oops, not standard deviation.
00:52
It would be times the square root of p hat times one minus p hat, divided by our sample size.
00:59
So we need to find our z score that we're going to be using here...