Which of the following is NOT true about correlations?  A. The closer to 0, the stronger the correlation. B. A positive correlation represents that as one variable increases, the other    variable also increases C. Correlations deal with quantitative variables. D. Correlations can only range from -1 to 1.   2. Which correlation is the strongest? A. 0.69 B. -0.78 C. 0.02 D. 0.77   3. Which correlation is the weakest? A. 0.32 B. 0.07 C. 0.99 D. -0.08

A2. A study of test results at different schools shows that as the student-to-teacher ratio increases the average test result tends to decrease, although the relationship is quite weak. Which of the following is plausible value for the correlation between student-to- teacher ratio and average test results? A -0.9 B -0.3 C -0.01 D 0.3 E 0.9

E4-45

Bt.20.

Which of the following is a plausible correlation for a person’s height and age from birth to age 10? a. 0.89 b. 0 c. -0.89

4.

The strength of the correlation is indicated by a number value and the closer that value is to zero, the weaker the correlation. O True O False

1. Correlation basics Which of the following statements about correlation are true? Check all that apply. If the correlation between two variables is close to 1, there is a positive linear relationship between the two variables. The sign of the correlation indicates the strength or consistency of the linear relationship between two variables. If the correlation between two variables is 0, there is no clear linear relationship between the two variables. The sign of the correlation indicates the direction of the relationship between two variables. Correlation measures and describes the behavior of a single variable. The correlation is scaleless; that is, it doesn't change when the measurement units are changed for either or both of the variables. The correlation indicates the strength and the direction of the linear relationship between two variables. O O O O O