00:01
For this question, let me just take notes what's given here.
00:04
So we have to find, so the proportion was given here, which is 30%.
00:10
I can write this as 0 .3, and the sample size was given as 260.
00:16
So, and the confidence level here given us, the confidence level, which was given as 99%.
00:22
So first of all, we're going to find the confidence interval for this question.
00:27
The confidence interval has the formula which is the proportion n plus 1 minus this is the alpha over 2 times the square of p times 1 minus p and divided by n this is the formula here first of all let's get the z alpha over 2 we know that the alpha is equal 1 minus confidence level so the alpha over 2 this is 1 minus 0 .99 which is 99 % divided by 2 which would be this is 0 .005 so to get the z alpha over 2 i'm going to use the in the graph, and display, calculate your application, the inverse norm, and the area from left to right.
01:00
This is the mean for the standard number distribution is zero, and the standard division is one.
01:05
Press second variance, the inverse norm here.
01:08
This is 0 .005, the mean and the standard division...