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

question 12

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

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Definitions:

Price

The sum of money anticipated, needed, or handed over in exchange for something.

Consumer Surplus I

The gap between what consumers are prepared and able to spend on a product or service and what they end up paying.

Price

The amount of money required to purchase a good or service.

Comparative Advantage

The ability of an individual, firm, or country to produce a good or service at a lower opportunity cost than other producers.