12.40 LCD TVs As technology improves, the choice of televisions becomes more compli- cated. Should you choose an LCD TV, an LED TV, or a plasma TV? Does the price of an LCD TV depend on the size of the screen? In the table below, Consumer Reports gives the prices and screen sizes for the top 10 LCD TVs in the 46-inch and higher categories.

a. Suppose that we assume that the relation- ship between size and price is linear, and per- form a linear regression, resulting in a value of 20.027. What does the value of r2 tell you about the strength of the relationship between price and screen size?

b. The diagnostic plots for this data are shown below. Does it appear that either the normality or equal variance assumptions have been violated?

c. Use a scatterplot to plot price versus screen size for the 10 LCD TVs. Based on the information in part

a, which assumption for the linear regression model has been violated?

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Brand Sony Bravia KDL-52NX800 Samsung LN55C650 Vizio VF550M Price (S) Size 2340 52 1600 55 1330 55 Sony Bravia KDL-60EX700 2700 60 Sharp Aquos LED LC-52LE700UN 1620 52 Sony Bravia KDL-46XBR10 2500 46 Samsung UN46C8000 2200 46 Vizio SV472XVT 1400 47 Samsung UN46C7000 LG 47LD450 2100 46 900 47