### Comparison of computer hard drives

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##### Reference no: EM13977534

1. In a PC World comparison of computer hard  drives, data describing the drives included the following variables: price (dollars), disk capacity (gigabytes), and rotational speed (RPM). The data are in file XR17027. With 5 price, x1 5 disk capacity, and x2 5 rotational speed (coded as 1 5 7200 RPM and 0 5 5400 RPM), determine the linear regression equation for estimating price as a function of the two predictor variables and interpret the partial regression coefficients. For a given storage capacity, how much extra would one expect to pay for a hard drive with the higher rotational speed?  Source: Stan Miastkowski,

2. For a small sample of suburban homes recently sold, the selling price (\$), living space (square feet), and suburban area (Sunny Haven, Easy Acres, or Rolling Hills) have been recorded. Given the data shown here, determine the linear regression equation for estimating selling price based on the other variables. For any qualita- tive variables that are used, be sure to specify the coding strategy employed for each. Comment on the explanatory power of the regression equation and interpret the partial regression coefficients.

 "Livin' Large," PC World, March 2001, p. 109. Home Price Space Area 17.28  A researcher has observed 50 automatic   teller 1 167,900 2860 Easy machine (ATM)  users outside the gift shop of a    museum, 2 184,800 2050 Sunny and the data are in file XR17028. With y 5 amount  with- 3 161,000 2110 Rolling drawn (dollars), x1 5 time required for the transaction 4 160,800 2950 Easy (seconds), and x2 5 gender (1 5 female, 0 5 male), 5 148,200 1570 Sunny determine the linear regression equation for estimating 6 128,600 1860 Rolling the withdrawal amount as a function of the two predic- 7 145,700 2620 Rolling tor variables and interpret the partial regression  coef- 8 178,500 2010 Sunny ficients. According to the equation, how much    difference 9 146,100 2710 Easy does gender tend to make in the amount   withdrawn? 10 146,300 2200 Rolling

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#### Determine the least-squares regression line

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