00:01
Okay, so i've written the equation here for how to calculate the confidence interval.
00:11
So i have confidence interval as equal to x.
00:17
This represents the mean.
00:25
Plus or minus, we are going to, at some point, use the plus, and that will give us our higher value of our interval.
00:35
And then we will later use the minus, which will give us the lower value of our interval.
00:42
C is used to represent the confidence level.
00:56
S will be the standard deviation, and n will represent our population size.
01:22
Okay, so let's fill in the values that we have to calculate our confidence interval.
01:30
Confidence interval is equal to.
01:33
Now, we are given the mean.
01:35
And the mean is 46 .4 plus or minus z.
01:42
Z is the confidence level, and z is a set value based on what you want your confidence interval to be.
01:53
So we want a 97 % confidence interval, and the z value for that is 2 .17009.
02:04
And you can look this up on any table.
02:06
Usually you will be given a table of percentages for confidence intervals.
02:14
So 90%, 80%, in this case, it's 97%, and you can find on the table what z value corresponds to 97%, which is 2 .17 .009...