(a) Assume both the wage distribution of people with a bachelor degree and the wage distribution of people without a bachelor degree follow normal distribution and having mean u1 and u0 respectively. Write down the estimators for u1 and u0 respectively.

(b) Write down the (null and alternative) hypotheses that difference between the average wages of people with a bachelor degree and people without a bachelor degree is zero. Then write down test statistic for the hypothesis test(Assume the variances of the two groups are not equal) and the p-value for the test.

(c) Construct a 1 confidence interval for u1 u0.