4. In a sample of 10 people in Japan average lifeexpectancy is 85 years with a sample standard deviation of 3 years.In a sample of 8 people in South Korea, the corresponding numbersare 82 years and 2 years.
(a) Find a 95% confidence interval for the populationaverage difference in life expectancy.
(b) Suppose you wish to test the null that the twopopulation life expectancy values are equal against the alternativethat they are different. Find a range in which the P-value mustfall.
