00:01
Hey there, welcome to numerate.
00:03
So we are looking at the percentage of campus student body, the percentage of being females.
00:11
So we're looking at the proportion of women's students on campus, basically.
00:15
For part a, we're trying to be 99 % confident that the population proportion would be a distance of 0 .07 from the proportion, given no prior estimate here.
00:28
So our equation that we're going to use for parts a and b will be the margin of error equation, and then we're going to manipulate it to solve for n.
00:42
So therefore, a margin of error equals z critical value, multiplied by the square root of a proportion times 1 minus our proportion divided by n.
01:02
So we're going to solve for n.
01:04
Therefore n will equal our proportion times one minus our proportion divided by our margin of error divided by the z critical value square so basically what we did first is to move the z critical value to the left side and then we're going to square both sides and we move n to the left and move the margin of error divided by the z critical value back to the right which is divided by dot square.
01:44
Okay.
01:45
This is how we got the manipulation equation here.
01:48
So let's plug in our values.
01:50
Since we are given no prior estimates here, our proportion will be 0 .5.
01:56
1 minus 0 .5 will be 0 .5.
01:59
So this will be divided by.
02:03
Our margin of error.
02:05
So our margin of error is given to us within a distance of 0 .0 .0.
02:12
7 divided by our z critical value.
02:21
So our z critical value is based off a 99 % confidence, given us a critical value of around 2 .58.
02:36
And this is going to be squared...