The article Air Pollution and Medical Care Use by Older Americans (Health Affairs [2002]: 207 214) gave

The article €œAir Pollution and Medical Care Use by Older Americans€ (Health Affairs [2002]: 207€“ 214) gave data on a measure of pollution (in micrograms of particulate matter per cubic meter of air) and the cost of medical care per person over age 65 for six geographical regions of the United States:

a. If the goal is to learn how cost of medical care is related to pollution, which of these two variables is the response variable and which is the predictor variable?
b. Construct a scatterplot of these data. Describe any interesting features of the scatterplot.
c. Find the equation of the least squares regression line for predicting medical cost using pollution.
d. Is the slope of the least squares line positive or negative? Is this consistent with the scatter plot in Part (b)?
e. Do the scatterplot and the equation of the least squares regression line support the researchers€™ conclusion that elderly people who live in more polluted areas have higher medical costs? Explain.
f. What is the predicted cost of medical care for a region that has a pollution measure of 35?
g. Would you use the least squares regression equation to predict cost of medical care for a region that has a pollution measure of 60? If so, what is the predicted cost of medical care? If not, explain why.

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COUPolitionCost of Medical care Region North Upper South Deep South West South Big Sky West 30.0 31.8 32.1 26.8 30.4 40.0 915 891 968 972 952 899