00:01
So for this question, we're going to construct a 95 % confidence interval.
00:06
We have 25 data points, we have an average of 6 .2 and a standard deviation of 5 .1.
00:12
Now it's mentioned in the problem that it's a normal distribution.
00:17
Now when you have a normal distribution, you should be able to approximate your sample standard deviation with the population standard deviation, and then we can use a z confidence interval.
00:28
However, sometimes for more conservative approaches, one might use a t interval instead, where you'll have basically the same formula, but it'll be a slightly wider confidence interval.
00:43
I'm going to do this problem using the assumption that it's normal, and we're going to do a z confidence interval.
00:49
So what will this look like? well, the formula for the confidence interval is your average plus or minus a critical z value times the standard deviation over square root n...