Retail Price Data for N = 60 Hard Disk Drives $y =$

Multiple Choice

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: $y =$ Retail PRICE (measured in dollars)
$x _ { 1 } =$ 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:
$$\begin{array}{lllllllll}\hline &&&\text { Dep Var }&\text {Predict }&\text {Std Err}&\text { Lower 95\%}&\text { Upper 95\% }\\ \text {OBS }&\text {SPEED }&\text {CHIP }&\text {PRICE}&\text { Value }&\text {Predict }&\text {Predict}&\text { Predict }&\text {Residual}\\1 & 33 & 286 & 5099.0 & 4464.9 & 260.768 & 3942.7 & 4987.1 & 634.1\\\hline \end{array}$$
Interpret the interval given in the printout.

A) We are 95% confident that the price of a single hard drive with 33 megahertz speed and 386 CPU falls between $3,943 and $4,987.
B) We are 95% confident that the price of a single hard drive falls between $3,943 and $4,987.
C) We are 95% confident that the average price of all hard drives falls between $3,943 and $4,987.
D) We are 95% confident that the average price of all hard drives with 33 megahertz speed and 386 CPU falls between $3,943 and $4,987.