A sociologist surveys 50 randomly selected citizens in each oftwo countries to compare the mean number of hours of volunteer workdone by adults in each. Among the 50 inhabitants of Lilliput, themean hours of volunteer work per year was 52, with standarddeviation 11.8. Among the 50 inhabitants of Blefuscu, the meannumber of hours of volunteer work per year was 37, with standarddeviation 7.2.
Construct the 99% confidence interval for the difference in meannumber of hours volunteered by all residents of Lilliput and themean number of hours volunteered by all residents of Blefuscu.
Test, at the 1% level of significance, the claim that the meannumber of hours volunteered by all residents of Lilliput is morethan ten hours greater than the mean number of hours volunteered byall residents of Blefuscu.
Compute the observed significance of the test in part (b).
