Retail Price Data for N = 60 Hard Disk Drives $\mathrm { y } =$

Essay

Retail price data for n = 60 hard disk drives were recently reported in a computer magazine. Three variables were recorded for each hard disk drive: $\mathrm { y } =$ Retail PRICE (measured in dollars)
$\mathrm { x } _ { 1 } =$ Microprocessor SPEED (measured in megahertz)
(Values in sample range from 10 to 40 )
$x _ { 2 } =$ CHIP size (measured in computer processing units)
(Values in sample range from 286 to 486 )
A first-order regression model was fit to the data. Part of the printout follows:

$$\begin{array}{lllllllll}\hline &&&\text { Dep Var }&\text {Predict }&\text {Std Err}&\text { Lower 95\%}&\text { Upper 95\% }\\ \text {OBS }&\text {SPEED }&\text {CHIP }&\text {PRICE}&\text { Value }&\text {Predict }&\text {Predict}&\text { Predict }&\text {Residual}\\1 & 33 & 386 & 5099.0 & 4464.9 & 260.768 & 3942.7 & 4987.1 & 634.1\\\hline \end{array}$$


Interpret the $95 \%$ prediction interval for $y$ when $x _ { 1 } = 33$ and $x _ { 2 } = 386$ . 2 Find and Interpret Confidence Interval