2.160 Faculty salaries. Here are the salaries for a sample of professors in a mathematics department at a large midwestern university for the academic years 2014–2015 and 2015–2016.
| 2014–2015 | 2015–2016 | 2014–2015 | 2015–2016 |
|---|---|---|---|
| salary ($) | salary ($) | salary ($) | salary ($) |
| 145,700 | 147,700 | 136,650 | 138,650 |
| 112,700 | 114,660 | 132,160 | 134,150 |
| 109,200 | 111,400 | 74,290 | 76,590 |
| 98,800 | 101,900 | 74,500 | 77,000 |
| 112,000 | 113,000 | 83,000 | 85,400 |
| 111,790 | 113,800 | 141,850 | 143,830 |
| 103,500 | 105,700 | 122,500 | 124,510 |
| 149,000 | 150,900 | 115,100 | 117,100 |
(a) Construct a scatterplot with the 2015–2016 salaries on the vertical axis and the 2014–2015 salaries on the horizontal axis.
(b) Comment on the form, direction, and strength of the relationship in your scatterplot.
(c) What proportion of the variation in 2015–2016 salaries is explained by 2014–2015 salaries?