Question

The correlation coefficient for the ages of driver safety class and the number of traffic violations they have received is -0.61.
How are the ages and numbers of violations related?

A. As age increases, violations increase.

B. As age increased, violations remain the same.

C. As age increased, violations decrease.

D. There is no association between age and number of violations.

Answer 1

Solution: We are given that the correlation coefficient between ages and numbers of violations is -0.61.

The ages and numbers of violations related as age increases, violations decrease.

Therefore, the option c. as age increases, violations decrease.

The correlation coefficient measures the strength of linear association between two variables. The value of the correlation lies between -1 to 1. -1 indicates the perfect negative linear relationship between two variables. The negative values of correlation means as the one variable increases, the other variable decreases. The correlation of +1 indicates that there is perfect positive linear relationship between two variables. The positive values of correlation means as the one variable increases, the other variable also increases.

In the above statement the correlation value is negative, therefore indicating as age increases, violations decrease.