Recently, the annual numbers of driver deaths per 100,000 people for the selected age groups are as follows:
| Age (years) | Number of Driver Deaths (per 100,000 people) |
| 1619 | 38 |
| 2024 | 36 |
| 2534 | 24 |
| 3554 | 20 |
| 5574 | 18 |
| 75+ | 28 |
- For each age group, pick the midpoint of the interval for the x value. For the 75+ group, use 80.
- Using age as the independent variable and number of driver deaths per 100,000 people as the dependent variable, make a scatter plot of the data.
- Calculate the least-squares (best–fit) line. Put the equation in the form ŷ = a + bx.
- Find the correlation coefficient. Is it significant?
- Predict the number of deaths for ages 40 years and 60 years.
- Based on the given data, is there a linear relationship between age of a driver and driver fatality rate?
- What is the slope of the least-squares (best-fit) line? Interpret the slope.
OpenStax Statistics, 12.4 Prediction (Optional), exercise 23