This problem has to do with the wetting depth of soil and the ages of 21 houses. Use the accompanying data.
| x |
y |
| 2.52 |
54.74 |
| 2.87 |
59.01 |
| 3.05 |
72.92 |
| 3.43 |
50.85 |
| 3.68 |
54.99 |
| 3.76 |
60.56 |
| 3.76 |
69.08 |
| 4.5 |
77.03 |
| 4.5 |
69.97 |
| 5.26 |
90.7 |
(a) Compute the least squares line.
(b) Give a 95% confidence interval for the slope.