A Public Health Researcher Wants to Use Regression to Predict $\quad \mathrm { y } =$

question 89

Multiple Choice

A public health researcher wants to use regression to predict the sun safety knowledge of pre-school children. The researcher randomly sampled 35 preschoolers, assigned them to one of
Two groups, and then measured the following three variables: SUNSCORE: $\quad \mathrm { y } =$ Score on sun-safety comprehension test
READING: $\quad \mathrm { x } _ { 1 } =$ Reading comprehension score
GROUP: $\quad x _ { 2 } = 1$ if child received a Be Sun Safe demonstration, 0 if not
A regression model was fit and the following residual plot was observed.

Which of the following assumptions appears violated based on this plot?

• A)The mean of the errors is zero
• B)The errors are independent
• C)The errors are normally distributed
• D)The variance of the errors is constant

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Definitions:

Accumulated Depreciation

The total depreciation for a fixed asset that has been charged to expense since the asset was acquired.

Gain on Sale

The income generated when an asset is sold at a value higher than its original cost or book value.

Machinery

Heavy and complex machines or equipment used in various industries for manufacturing, construction, or specific tasks requiring mechanical force.

Book Value

The value of an asset as recorded on the balance sheet, calculated by subtracting any associated depreciation or amortization from its original cost.