Retail Price Data for N = 60 Hard Disk Drives

question 67

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:
$\begin{aligned} y = & \text { Retail PRICE (measured in dollars) } \\ x _ { 1 } = & \text { Microprocessor SPEED (measured in megahertz) } \\ & \text { (Values in sample range from } 10 \text { to } 40 \text { ) } \\ x _ { 2 } = & \text { CHIP size (measured in computer processing units) } \\ & \text { (Values in sample range from } 286 \text { to } 486 \text { ) } \end{aligned}$
A first-order regression model. was fit to the data. Part of the printout follows:
$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$ Parameter Estimates
$\quad$$\quad$$\quad$$\quad$$\quad$ PARAMETER STANDARD $\quad$ T FOR 0 :
VARIABLE DF ESTIMATE ERROR PARAMETER $= 0$ PROB $> | \mathrm { T } |$
$\begin{array} { l r l l l l } \text { INTERCEPT } &1 & - 373.526392 & 1258.1243396 & - 0.297 & 0.7676 \\\text { SPEED } & 1 & 104.838940 & 22.36298195 & 4.688 & 0.0001 \\\text { CHIP } & 1 & 3.571850 & 3.89422935 & 0.917 & 0.3629\end{array}$


$\text { Identify and interpret the estimate of } \beta_{2} \text {. }$

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Definitions:

Cones

Photoreceptor cells in the retina of the eye that are responsible for color vision and function best in relatively bright light.

Rods

Photoreceptor cells in the retina that are highly sensitive to light, allowing for vision in low light conditions but not in color.

Feature-Detector Cells

Neurons in the brain that respond to specific features of a stimulus, such as lines, edges, or movement.

Visual Cortex

The part of the cerebral cortex that receives and processes sensory nerve impulses from the eyes.