00:01
Hello, so here we've been given a confidence interval of 99%.
00:09
The actual interval has been given to be from 0 .27 to 0 .42.
00:20
A, we want to find the sample proportion.
00:23
P, that is given by 0 .27 plus 0 .42 divided by 2.
00:36
So let's look at 0 .27 plus 0 .42 divided by 2.
00:48
Sample proportion is 0 .345.
01:01
Margin of error e is given by 0 .42 minus 0 .27 divided by 2.
01:24
That is going to be 0 .075.
01:30
C, we want to know the critical value.
01:37
So the critical value, we're going to find that using alpha, which is 1 minus confidence level.
01:44
So that's 1 minus 0 .99.
01:48
You get 0 .01.
01:53
If you divide by 2, you're going to have 0 .005.
02:02
The critical value, which is the z value, is 1.
02:09
This is not a 10%.
02:11
So from the z table, this is going to be 2 .0.
02:13
0 .576.
02:19
So you just need to look up this value from the z table.
02:23
The corresponding z value, which is the critical value is positive...