The average number of people in a family who attended college for various years is given in the table.
| Year | No. of Family Members Attending College |
| 1969 | 4.0 |
| 1973 | 3.6 |
| 1975 | 3.2 |
| 1979 | 3.0 |
| 1983 | 3.0 |
| 1988 | 3.0 |
| 1991 | 2.9 |
- Using year as the independent variable and number of family members attending college as the dependent variable, draw a scatter plot of the data.
- Calculate the least-squares line. Put the equation in the form ŷ = a + bx.
- Does the y-intercept, a, have any meaning here?
- Find the correlation coefficient. Is it significant?
- Pick two years between 1969 and 1991 and find the estimated number of family members attending college.
- Based on the data in the table, is there a linear relationship between the year and the average number of family members attending college?
- Using the least-squares line, estimate the number of family members attending college for 1960 and 1995. Does the least-squares line give an accurate estimate for those years? Explain why or why not.
- Are there any outliers in the data?
- What is the estimated average number of family members attending college for 1986? Does the least-squares line give an accurate estimate for that year? Explain why or why not.
- What is the slope of the least-squares (best-fit) line? Interpret the slope.
OpenStax Statistics, 12.5 Outliers, exercise 21