The following scatterplots display the age (in months) at which a child first speaks and the child's score on a cognitive aptitude test taken later in childhood.
Graph A (on the left) displays all of the data in a sample, and Graph B (on the right) excludes the two children who took longer than 24 months to speak.
In one of these graphs the correlation coefficient is -.034, and in the other graph the correlation coefficient is -.640.
a. Identify which correlation coefficient goes with Graph A (on the left). Briefly explain your choice.
b. Write a paragraph, as if to the parent of an infant, summarizing what these scatterplots reveal about whether there is a relationship between the age at which a child first speaks and his/her cognitive aptitude.

Question

The following scatterplots display the age (in months) at which a child first speaks and the child's score on a cognitive aptitude test taken later in childhood.
Graph A (on the left) displays all of the data in a sample, and Graph B (on the right) excludes the two children who took longer than 24 months to speak.
  In one of these graphs the correlation coefficient is -.034, and in the other graph the correlation coefficient is -.640.
a. Identify which correlation coefficient goes with Graph A (on the left). Briefly explain your choice.
b. Write a paragraph, as if to the parent of an infant, summarizing what these scatterplots reveal about whether there is a relationship between the age at which a child first speaks and his/her cognitive aptitude.

Quizplus · Accepted Answer

The Answer of The following scatterplots display the age (in months) at which a child first speaks and the child's score on a cognitive aptitude test taken later in childhood.
Graph A (on the left) displays all of the data in a sample, and Graph B (on the right) excludes the two children who took longer than 24 months to speak.
  In one of these graphs the correlation coefficient is -.034, and in the other graph the correlation coefficient is -.640.
a. Identify which correlation coefficient goes with Graph A (on the left). Briefly explain your choice.
b. Write a paragraph, as if to the parent of an infant, summarizing what these scatterplots reveal about whether there is a relationship between the age at which a child first speaks and his/her cognitive aptitude.

The Following Scatterplots Display the Age (In Months) at Which