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:

Long Tail

A business strategy that allows companies to realize significant profits by selling low volumes of hard-to-find items to many customers, instead of only selling large volumes of a reduced number of popular items.

Feature Creep

The tendency for products to become overly complex due to the continuous adding of features, often compromising usability and functionality.

Inert Set

A group of brands that a consumer is aware of but is indifferent towards when making a purchase decision.

Brand Choices

The decision process and factors influencing why consumers prefer one brand over others within a product category.