11. An economist wants to determine the relation between one's credit score and the interest rate (as a percentage) of a 36-month auto loan. The table below shows the data collected from a random sample of 6 individuals. Credit Score Interest Rate (as a percentage) 545 18.9 595 16.9 640 12.2 675 8.6 705 6.7 750 5.2

a) (5pts) Use your calculator to help sketch a scatterplot of the data treating credit score as the explanatory variable. Label axes with variable names.

b) (5pts) Find the line-of-best-fit for the scatter plot in part (a).

c) (5pts) Interpret the numeric value of the slope in the context of this problem.

d) (5pts) Karla has a credit score of 634. Predict the interest rate she would pay. If this value should not be computed, state why.