Question 4: Instructor claims that his new training program will improve the IQ score of undergraduate students. To test his claim at the level a = 0.05, we selected a sample of 5 students and observed their IQ scores before and after the program. The results are given below: 2 3 Sum Student IQ score before IQ score after Difference 1 87 89 90 95 100 104 4 103 106 5 111 112 Do you agree with the claim of the instructor? (a) State your null and alternative hypotheses? (b) Calculate the test statistic. (c) Set up the rejection region for the hypotheses? (d) Construct the 95% confidence interval of the mean difference between the two means (mean before - mean after). What this tells us?​