4. If you obtained one thousand 95% confidence intervals for a population mean, roughly how many of the intervals would actually contain u? (1 mark) 5. The following table gives the age (in years) of 36 randomly selected U.S. millionaires. The sample mean x=i 58.53 years. Assume that the standard deviation of the ages of all U.S. millionaires is 13.0 years. 31 45 79 64 48 38 39 68 52 59 68 79 42 79 53 74 66 66 71 61 52 47 39 54 67 55 71 77 64 60 75 42 69 48 57 48 (a) Test at the 5% significance level whether the average year of age of all U.S. millionaires is below 60 years. (8 marks) (b) What is the P-value of the hypothesis test in part (a)? (2 marks)