00:01
So for this question, we're going to start by identifying all the different parts, and then we're going to compute a 90 % confidence interval.
00:09
So for a, we're asked to identify x bar.
00:13
So that's our sample mean.
00:14
So if we read the question, we see that the sample mean is found to be 32.
00:27
So that's x bar.
00:29
And next, we're asked to identify sigma.
00:32
So remember, that's our standard deviation.
00:35
And the question tells us that the standard deviation of the population is known and that its value is 2 .4.
00:42
For c, we're asked to identify n, so the number of observations in the sample, and we're told that it's a sample of 64 measurements.
00:54
Next, we're asked to identify 1 minus alpha.
00:58
So we're going to get that from knowing what percent confidence interval we're going to have.
01:04
So we're told that it's a 90 % confidence interval, which tells us that alpha is 0 .1.
01:13
So 1 minus alpha is 1 minus 0 .1, which is equal to 0 .9...