0:00
All right.
00:02
So for this question, we want to find the 90 % confidence interval for danish coffee drinkers.
00:11
Now, in this problem, it says that you're supposed to have a file that contains a random sample of 144 coffee drinkers and how many kilograms of coffee they consumed.
00:27
But since you didn't provide that data, i made up some data so that i can talk you through the explanation.
00:35
What we're going to do is i have open here in google sheets.
00:42
I don't know if you have a different software that you're using.
00:46
If you do, the steps will be slightly different.
00:50
If you're doing it by hand, it will be the same process, but you have to do it with the formulas.
00:55
Is i don't think they would make you do a sample of 144 by hand.
00:59
I assume that since they're providing you with a csv, that you can use technology.
01:05
So the first step is to find the mean of your sample.
01:10
What we're going to do is we're going to find the average of our sample, which here is cell a1 through cell a144.
01:21
So according to this, our mean is about 5 .1 .5 .1.
01:25
One.
01:27
Next we're going to find our standard deviation and that is again the same data.
01:37
So our standard deviation is about three.
01:41
Next we're going to find the range of our confidence interval which we can just type in confidence and then go down to confidence t...