A sample containing years to maturity and yield for 40 corporatebonds are contained in the data given below.
| Years to Maturity | Yield | | Years to Maturity | Yield |
|---|
| 23.50 | | 4.757 | | 3.75 | | 2.769 |
| 21.75 | | 2.473 | | 12.00 | | 6.293 |
| 21.50 | | 4.464 | | 17.50 | | 7.411 |
| 23.50 | | 4.684 | | 18.00 | | 3.558 |
| 27.00 | | 4.799 | | 8.25 | | 0.945 |
| 18.25 | | 3.755 | | 23.25 | | 2.966 |
| 15.75 | | 7.068 | | 14.75 | | 1.476 |
| 2.00 | | 7.043 | | 10.00 | | 1.382 |
| 8.75 | | 6.540 | | 23.00 | | 6.334 |
| 5.25 | | 7.000 | | 15.25 | | 0.887 |
| 11.25 | | 4.823 | | 4.75 | | 4.810 |
| 25.75 | | 1.874 | | 18.00 | | 1.238 |
| 14.25 | | 5.654 | | 3.00 | | 6.767 |
| 19.25 | | 1.745 | | 9.50 | | 3.745 |
| 25.00 | | 8.153 | | 17.50 | | 4.186 |
| 6.75 | | 6.571 | | 17.00 | | 5.991 |
| 23.00 | | 7.506 | | 9.50 | | 7.322 |
| 19.00 | | 2.857 | | 5.50 | | 4.871 |
| 10.75 | | 8.010 | | 27.50 | | 2.403 |
| 21.25 | | 4.214 | | 26.00 | | 4.500 |
a. What is the sample mean years to maturityfor corporate bonds and what is the sample standard deviation?
| Mean | ？ (to 4 decimals) |
| Standard deviation | ？ (to 4 decimals) |
b. Develop a 95% confidence interval for thepopulation mean years to maturity. Round the answer to four decimalplaces.
（ , ） years
c. What is the sample mean yield on corporatebonds and what is the sample standard deviation?
| Mean | ？(to 4 decimals) |
| Standard deviation | ？(to 4 decimals) |
d. Develop a 95% confidence interval for thepopulation mean yield on corporate bonds. Round the answer to fourdecimal places.
（ , ）percent
