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. The residual plot below was obtained by the researchers. The plot does not show any obvious model violations because:
A)there is no pattern in the plot.
B)the residuals are spread evenly around the horizontal line through zero.
C)there are no obvious outliers.
D)All of the answer options are correct.

Question

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. The residual plot below was obtained by the researchers.  The plot does not show any obvious model violations because:
A)there is no pattern in the plot. 
B)the residuals are spread evenly around the horizontal line through zero. 
C)there are no obvious outliers. 
D)All of the answer options are correct.

Quizplus · Accepted Answer

The residual plot shows no pattern, indicating that the linear regression model is appropriate. The residuals are spread evenly around the horizontal line through zero, indicating that the model is unbiased. There are no obvious outliers, suggesting that the model is not influenced by extreme values, and the fact that all answer options are correct confirms that the plot does not show any obvious model violations.

A Study of Obesity Risk in Children in a Head