00:01
In this problem, we are given all of the necessary details about a sample, and we are being instructed to construct the indicated confidence interval for the population mean, m using a t distribution.
00:16
So just to recap, in a t distribution, what we're working with is that we don't know what the population standard deviation sigma is, and we have to work with the sample standard deviation, which is given as s.
00:32
Now, in this problem, we are given that we want a 0 .9 confidence level.
00:39
So we want a 90 % confidence interval.
00:44
And we also are given that the mean of xx bar is equal to 12 .5.
00:53
And we're given that the sample standard deviation is 2 .0, but once again, we don't know the population standard deviation.
01:00
And we're given that the sample size n is equal to 6.
01:05
Now, to use a t distribution, the first thing we need to do is find the t value, tc.
01:19
And to do this, we need to find the degrees of freedom, and we also need to know the level of confidence.
01:28
So the degrees of freedom are equal to n minus 1, which is 6 minus 1, which is equal to 5...