A Study of Obesity Risk in Children in a Head

question 24

Multiple Choice

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 130 children. The researchers used a linear regression model for the prediction of BMI percentile. The food scores ranged from 45 to 245. Fifteen children had a food score of 170. A boxplot of those 15 children showed BMI percentile to be very skewed. This information is:

• A)irrelevant, because the relationship between food score and BMI percentile is being studied, not the BMI percentile values themselves.
• B)important, because one requirement for the validity of inference is that BMI percentile is Normally distributed at each value of the food score.
• C)irrelevant, as long as variation about the regression line is constant.
• D)probably due to some outlier and should simply be ignored.

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Definitions:

Value Weighted Index

An index in which each constituent is weighted according to its market value, reflecting the performance of the market based on total capitalization.

Share Weighted Index

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Price Weighted Index

A stock market index in which each company's stock influences the index in proportion to its price per share.

Adjustable Rate Mortgage

A type of mortgage in which the interest rate applied on the outstanding balance varies throughout the life of the loan according to market conditions.