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6-41.

Fabienne compared annual grocery bills with the other mothers at her church. She discovered a linear relationship between the total cost (in dollars) of groceries and the number of miles the mother lived from the downtown church. 6-41 HW eTool (Desmos).

1. Do you think that the association would be positive or negative? Strong or weak?

Recall the standards for a weak/strong association.

2. The upper boundary for Fabienne’s prediction was modeled by g = 11.27 – 0.14d where g is the cost of groceries (in thousands of dollars) and d is the distance from church (miles). The lower boundary was g = 7.67 – 0.14d. Estimate the equation of Fabienne’s line of best fit.

The y-intercept should be approximately halfway between 11.27 and 7.67. (Find a number that is halfway).

g = 9.47 − 0.14d

3. Interpret the slope of Fabienne’s model in context.

The slope is represented by −0.14 in the equation, but remember that we are working in thousands of dollars, so it would be $140. What is the slope saying about the cost in relation to the number of miles? 4. Fabienne lives 8 miles from church. Her residual was$510. About how much did she spend on groceries this year?

• Substitute 8 in for d and evaluate.