a Notice the word downtown. This tells us that the church is in an urban area, which is generally more expensive. Therefore, there should be a negative association between annual grocery bills and the distance from the church. It should look something like below.
However the correlation is likely weak, as there are many factors that affect local food prices.
b The line of best fit has the same slope as the upper and lower boundary. It is also halfway between the boundaries. Therefore, by calculating the average of the boundary's y-intercepts we get the y-intercept of the line of best fit.
211.27+7.67=9.47
The line of best fit is g=9.47−0.14d
c The slope is -0.14. This tells us that when the distance from the church increases by 1 mile, the annual grocery bill decreases on average by $140.
d By substituting d=8 we can find the predicted value for someone living 8 miles away.
Remembering that the value is in thousands of dollars, the expected amount spent on groceries is $8350. Notice that the residual was $510, which means the predicted value understates Fabienne's actual bill. By adding 510 to the predicted value, we get how much she spends on groceries this year.
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