00:01
Let me take notes what's given here.
00:02
First of all, the confidence level was given as 90 percent, and the sample mean, which is denoted by x bar, this is 347, and the sample standard division was given as 14 .5, and the sample size, which is denoted by n, this is 35.
00:19
So, we have to find the upper confidence limit for the sample mean, for the population mean, sorry.
00:25
The confidence interval for the population mean, which is x bar, this is plus or minus, we don't know the population standard division, so we have to use the t -test.
00:35
T alpha over 2 times sample standard division divided by square root of sample size.
00:41
Let's get first of all the alpha value, which is 1 minus confidence level...