13.26 You wish to study the relationship between the amount of sugar in a child’s breakfast and the child’s hyperactivity in school during the 4 hours after breakfast.

You ask 200 mothers of fifth-grade children to keep a careful record of what the children eat and drink each morning. Each parent’s report is analyzed, and the sugar consumption is determined. During the same time period, data on hyperactivity are collected at school. What statistic will measure the strength and kind of relationship that exists between the amount of sugar and the amount of hyperactivity?

Explain why the statistic you selected is appropriate and what value you expect this statistic might have.