Question: Questions 1-4 were to do with checking a sample against a set or known population mean. It is more common, however to use the t-test to compare two samples and to decide whether or not the two samples could have come from the populations with the same mean.

a) Using the Minitab worksheet called “furnace”, do some descriptive statistics on the variable btu.in and btu.out.

b) Do box plots on those two variables. Comment on the output.

c) Do a 2-sample t-test to compare the variables btu.in and btu.out. Your tutor will show you how to do this and what the output means

d) Sometimes if the data are paired as is the case here, the correct test to do is the paired t-test. Try this on the btu.in and btu.out data. Note differences between the output of this and part (c).

e) Finally try using the t-test to examine if there are differences between the male and female bears for the various numeric variables you have previously looked at.