On Correlation

1. For a certain class, the relationship between the amount of time spent studying and the test grade earned was examined. It was determined that as the amount of time they studied increased, so did their grades. This is a positive association.

• True

• False

2. For this same class, the relationship between the amount of time spent studying and the amount of time spent socializing per week was also examined. It was determined that the more hours they spent studying, the fewer hours they spent socializing. This is a negative association.

• True

• False

3. Two variables with a correlation of 0.3 have a stronger linear relationship than two variables with a correlation of -0.7.

• True

• False

4. It is possible for variables to have r = 0 but still have a strong association.

• True

• False

5. After polling a certain group of people, researchers found a 0.5 correlation between the number of car accidents per year and the driver’s age. This means that older people get in more accidents.

• True

• False

6. The correlation between R and T is the same as the correlation between T and R.

• True

• False

7. A correlation of r = 1.2 is not possible.

• True

• False

8. The correlation in real life between height and weight is r = 1.

• True

• False

9. Two variables with a correlation of -0.65 have a stronger linear relationship than two variables with a correlation of + 0.60.

• True

• False

10. The correlation of X and Y is 0.60, the correlation of X and W is -0.80. This indicates that ...

• X is more closely linearly related to Y

• X is more closely linearly related to W