00:01
Here we want to test the null hypothesis that a population mean is 28 versus the alternative hypothesis that the mean is greater than 28, and we are asked to test at a significance level of 0 .02.
00:14
To do so we have a random sample of 116 items drawn from the population, yielding a sample mean of 32.
00:23
Furthermore, we are told that the population is normally distributed, and that the standard deviation of the population is 8.
00:30
So in this situation, we happen to know the population standard deviation, so our test statistic is based on the standard normal distribution.
00:39
So let's first identify the critical values, or critical value.
00:44
This is a right -tailed hypothesis test, and we know that because the alternative hypothesis is a greater than hypothesis.
00:54
And for a right -tailed test, critical value, we denote it z sub alpha, or in this case, z sub 0 .02...