The exercise involving data in this and subsequent sections were designed to be solved using Excel.

PCWorld rated four component characteristics for 10 ultraportable laptop computers: features; performance; design; and price. Each characteristic was rated using a 0?100 point scale. An overall rating was then developed for each laptop. The following table shows the performance rating, features rating, and the overall rating for the 10 laptop computers ( PCWorld website, February 5, 2009). Click on the web file logo to reference the data.

Excel or Minitab users: The data set is available in file named Laptop. All data sets can be found in your eBook or on your Student CD.

Round your answers to four decimal places.

a. Determine the estimated regression equation that can be used to predict the overall rating using the performance rating as the independent variable.

? = + Performance

b. Determine the estimated regression equation that can be used to predict the overall rating using both the performance rating and the features rating.

? = + Performance + Features

c. Predict the overall rating for a laptop computer that has a performance rating of 80 and a features rating of 70.

Model Thinkpad X200 VGN-Z598U U6V Elitebook 2530P X360 Thinkpad X300 Ideapad U110 Micro Express JFT2500 Toughbook W7 HP Voodoo Envy 133 Performance 5 746 55 76 6 4 77 97 83 77 56 46 54 Features 87 85 80 75 80 76 81 73 79 68 Overall Rating 88 82 1 78 78 78 7 75 75 72 83 81 77 73