In: Statistics and Probability
1. Suppose the returns of a particular group of mutual funds are normally distributed with a mean of 9.7% and a standard deviation of 3.8%. If the manager of a particular fund wants to be sure that his fund is NOT in the bottom 25% of funds with the lowest return, what return must his fund have? (please round your answer to 2 decimal places).
2. Suppose the following data show the prices of 4 cars with similar characteristics that sold at a recent auction (in thousands of dollars): 6.6, 7.3, 13.7, 6. Calculate the standard deviation of the sample of selling prices. (please express your answer using 2 decimal places).
3. Suppose the profit the Honda dealership makes on the next 5 Accords it sells are: 433, 1,002, 752, 676, 1,322. What is the average profit on these cars?
4. In a sample of 84 people who have had strokes, the average cholesterol level was 254 with a standard deviation of 49.3. In order to test the hypothesis (at the 10% level of significance) that the average cholesterol level of people who have had strokes was at least 240, what is the critical value? (please round your answer to 2 decimal places)