A study of obesity risk in children in a head start program used a food score calculated from a 45-question food survey to predict body mass index (BMI) percentile in these children 18 months after the initial survey. The study enrolled 20 children. The researchers used a linear regression model for the prediction of BMI percentile. The food scores ranged from 45 to 245. "Linear" refers to which of the following?
A)Mean BMI percentile varies linearly with food score.
B)Variation about the regression line varies linearly with food score.
C)Each BMI percentile is linearly related to food score.
D)All of the answer options are correct.

Question

Quizplus · Accepted Answer

"Linear" in the context of a linear regression model means that the mean or expected value of the dependent variable (in this case, BMI percentile) varies linearly with the independent variable (food score). This implies a straight-line relationship between the two variables. Options B and C misinterpret the concept of linearity in regression analysis.

A Study of Obesity Risk in Children in a Head