00:01
We wish to test the claim that the mean volume of brains is 1 ,100 cubic centimeters, and we want to test at a 10 % significance level.
00:11
To do so, we have a random sample of 10 brains, volumes.
00:16
And so first we identify the hypotheses.
00:18
The null hypothesis is that the mean is 1100, and the alternative hypothesis that the mean is not 1100.
00:34
Now from the sample, we could calculate the sample standard deviation, but we don't know the population standard deviation, and therefore the standardized test statistic for this test follows a t distribution with n -1, or 9 degrees of freedom, and it's calculated as the sample mean minus the null -hypothesized mean, divided by the sample standard deviation, over the square root of the sample size.
01:05
So we need to find the sample mean and the sample standard deviation.
01:14
To do this, i've put the sample -standard deviation.
01:16
Data in excel.
01:21
So here are the 10 volumes of brains.
01:23
To calculate the sample mean, we use the average function, and we get 1157 .2, calculate the sample standard deviation, st -d -ev .s, function...