The table below shows the number of cars (in millions) sold in the United States for various years and the percent of those cars manufactured by GM.
Use a statistical software package to answer the following questions.
a. Is the number of cars sold directly or indirectly related to GM’s percentage of the market? Draw a scatter diagram to show your conclusion.
b. Determine the correlation coefficient between the two variables. Interpret the value.
c. Is it reasonable to conclude that there is a negative association between the two variables? Use the .01 significance level.
d. How much of the variation in GM’s market share is accounted for by the variation incars sold?
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