1) The number of motor vehicles registered (in

millions) in the U.S. has grown as follows:

Year Vehicles

(in millions)

1940 32.4

1945 31.0

1950 49.2

1955 62.7

1960 73.9

1965 90.4

1970 108.4

1975 132.9

1980 155.8

1985 171.7

a. Give a scatter-plot and residual plot of

the data.

b. Based on the graphs in part a, propose a

model for the data. Show me evidence

to support your conclusion. Go through

all necessary steps to construct a model

of the type you chose.

2)The public debt in the U.S. (in billions of

dollars) has grown as follows:

Year Spending

(in billions of dollars)

1910 2.65

1920 25.95

1930 16.19

1940 42.97

1950 257.36

1960 290.22

1970 389.16

1980 930.21

1990 3233.31

2000 5674.18

2010 13529.21

a. Give a scatter-plot and residual plot of

the data.

Based on the graphs in part a, propose a model for the data. Show me evidence to support your conclusion. Go through all necessary steps to construct a model of the type you chose.

3)The following table displays by gender the number of people who favor a particular flavor of ice cream. Chocolate Strawberry Vanilla Female 20 35 45 Male 30 25 50 a. Construct the marginal distributions of this table in counts. b. Draw a bar chart to display the marginal distribution of the ice cream preference for all people (use percentages). c. What percent of women prefer strawberry? d. Compare the conditional distributions of chocolate lovers and vanilla lovers. Briefly describe the most important differences between the two groups, and back up your description with percentages.