In Exercise 9.25 on page 555, we consider a regression equation to predict life expectancy from percent of government expenditure on health care, using data for a sample of 50 countries in SampCountries. Using technology and this dataset, find and interpret a 95% prediction interval for each of the following situations:
(a) Acountry which puts only 3% of its expenditure into health care.
(b) A country which puts 10% of its expenditure into health care.
(c) A country which puts 50% of its expenditure into health care.
(d) Calculate the widths of the intervals from (a), (b), and (c). What do you notice about these widths? (Note that for this sample, government expenditures on health care go from a minimum of 2.5% to a maximum of 26.0%, with a mean of 11.5%.)

Exercise 9.25

A random sample of 50 countries is stored in the dataset SampCountries. Two variables in the dataset are life expectancy (LifeExpectancy) and percentage of government expenditure spent on health care (Health) for each country.Weare interested in whether or not the percent spent on health care can be used to effectively predict life expectancy.