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

question 74

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: $\quad \quad x _ { 2 } = 1$ if child received a Be Sun Safe demonstration, 0 if not

A regression model was fit and the following residual plot was observed.
Predicted value of $y$

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

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

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Definitions:

Convert

To change something into a different form or properties, often referring to changing beliefs, units, or file formats.

Milliliters

A unit of volume in the metric system, commonly used to measure liquids, equal to one thousandth of a liter.

Convert

To change something into a different form or properties, often referring to religious beliefs, units of measurement, or file formats.

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A medication primarily used to treat seizures and neuropathic pain, as well as other conditions as prescribed by a healthcare provider.