00:01
We want to find the sample mean x -bah, the sample standard deviation s, and construct the 90 % confidence interval about the population mean mu for data below.
00:11
We assume a population is normally distributed, and once we compute these particular values, we want to interpret our findings.
00:18
To start off with, let's find x -bar and s.
00:21
Remember that to do so, we use appropriate definitions.
00:24
For x -bar, that is the sum of the data x -i divided by the n, the number of data points.
00:28
This computes the x -bar equals 62 .3.
00:31
S is defined as the square root of the sum of deviations about the mean square divided by n -1, which in this point computes to 8 .0.
00:39
Next, let's find the t -c value, or rather the critical t -value, from the student's c distribution needed to compute this confidence interval...