For each subject the researchers calculated the correlation

Question

Problem:

How well do people remember their past diet? Data are available for 91 people who were asked about their diet when they were 18 years old. Researchers asked them at about age 55 to describe their eating habits at age 18. For each subject, the researchers calculated the correlation between actual intakes of many foods at age 18 and the intakes the subjects now remember. The median of the 91 correlations was r = 0.217.⁵ Which of the following conclusions is consistent with this correlation?

Required:

(i) We conclude that subjects remember approximately 21.7% of their food intakes at age 18.

(ii) We conclude that subjects remember approximately r² = 0.217² = 0.047 of their food intakes at age 18.

(iii) We conclude that food intake at age 55 is about 21.7% that of food intake at age 18.

(iv) We conclude that memory of food intakes in the distant past is fair to poor.