kaplan7 - nishi

[ArchivalUser]

A study was conducted to examine the factors in the development of young children that can be used to predict intelligence in adults. For this study, 300 adults, all 45 years of age and stratified by socioeconomic status, were selected at random from a pool of over 1,000 volunteers. Those selected were given a standard IQ test battery and interviewed in detail about their memories of early childhood (between the ages of 4 and 6). The investigators wished to use Pearson correlation coefficients to assess both the statistical significance of the factors identified and the magnitude of the relationship between those factors and intelligence. Which of the following characteristics of childhood should be included in a study with this design?
A. Early instruction in how to play a musical instrument
B. Population of the town in which the child was raised
C. Presence of both parents in the household
D. Presence of siblings
E. Ranking within first grade class in school
F. Travel outside the United States prior to age 5

[ArchivalUser]

E??

[ArchivalUser]

I am confused between A and C--learning music at an early age has been linked to adult intelligence -so has a supportive childhood with presence of both parents.
A?

[ArchivalUser]

answer is B. A Pearson correlation coefficient looks for a linear relationship between two interval level variables. IQ is measured on an interval scale. The variable it is compared with must be on a linear scale as well. The population of the town in which the child was raised is the only interval level variable among the presented options, and therefore is the only possible answer. All of the other variables would be coded as either occurring or not occurring, that is, as nominal variables.