| Store | monthly sales (y) | online advertising cost (x) |
| 1 | 368 | 1.7 |
| 2 | 340 | 1.5 |
| 3 | 605 | 2.8 |
| 4 | 954 | 5 |
| 5 | 331 | 1.3 |
| 6 | 556 | 2.2 |
| 7 | 376 | 1.3 |
| 8 | 337 | 1.4 |
| 9 | 367 | 1.9 |
| 10 | 630 | 3 |
| (a) | pearson correlation coefficient between x and y | |
| 0.98 | ||
| scatter diagram and line of regression |
Pearson Correlation Coefficient: 936769
