Profit: Amazon.com The following table shows Amazon.com’s approximate net...

Profit: Amazon.com The following table shows Amazon.com’s approximate net sales (revenue) and net income (profit) in the period 2006–2009:

a. Use this information to find a linear regression model for Amazon’s net income I (in millions of dollars) as a function of net sales S (in billions of dollars).

b. Give the units of measurement and interpretation of the slope.

c. What, according to the model, would Amazon.com need to earn in net sales in order for its net income to be $1 billion? (Round answer to the nearest $ billion.)

d. Plot the data and regression line. Based on the graph, would you say that the linear model is reasonable? Why?