The percentages of elementary school children who receive free or reduced-fee lunches and the percentages of bicycle riders who wear helmets are shown in Table 15 for 13 Californian neighborhoods.

Let L be the percentage of children who receive free or reduced-fee school lunches, and let H = f (L) be the percentage of bicycle riders who wear helmets.
a. Construct a scatterplot, treating the percentage of children who receive reduced-fee or free school lunches as the explanatory variable.
b. Graph the model f (L) = -0.33 L + 43.64 on the scatterplot. Does it come close to most of the data points? Should it come close to the point for Los Arboles? Explain.
c. Find f(40). What does it mean in this situation?
d. Find L when f (L) = 40. What does it mean in this situation?
e. Does an increase in L cause a decrease in H? Explain. Describe at least one possible lurking variable.

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Table 15 Children Who Receive Free or Reduced-Fee School Lunches and Bicycle Riders Who Wear Helmets Percent Receiving Free or Reduced Percent Wearing Fee Lunches Neighborhood Fair Oaks Walnut Acres Bicycle Helmets 22.1 35.9 57.9 22.2 42.4 5.8 3.6 Discovery Bay 81 51 55.2 33.3 Toyon Lietz Los Arboles 19