Table P-16 contains data for 23 cities on newsprint consumption (Y) and the number of families in the city (X) during a particular year.

a. Plot newsprint consumption against number of families as a scatter diagram.
b. Is a simple linear regression model appropriate for the data in Table P-16? Be sure your answer includes an analysis of the residuals.
c. Consider a log transformation of newsprint consumption and a simple linear regression model relating Y = log (newsprint consumption) to X = number of families. Fit this model.
d. Examine the residuals from the regression in part c. Which model, the one in part b or the one in part c, is better? Justify your answer.
e. Using the fitted function in part c, forecast the amount of newsprint consumed in a year if a city has 10,000 families.
f. Can you think of other variables that are likely to influence the amount of newsprint consumed in a year?

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TABLE P-16 Newsprint Number of Consumption Families Newsprint Number Consamption Families of City (metric tons) City Y (metric tons) 8.600 13 6,870 14 9,880 15 12.370 16 6,920 17 3,760 18 7,450 19 6,700 20 7.420 21 6,930 22 7.400 23 7.420 878 637 3.291 2.470 916 525 1.159 1.138 979 1,899 5,022 8.330 9,010 11,790 18,910 8,550 8,850 8,540 6910 7.060 10.920 14,800 961 556 1,252 1,399 1,877 921 494 530 488 1253 10 12