A yoga instructor collected student data. He found that students who had less sleep did not tend to burn more or fewer calories during class. What can he conclude?

1. There isnocorrelation between amount of sleep and number of calories burned.
2. There is a correlation between amount of sleep and number of calories burned. There may or may not be causation. Further studies would have to be done to determine this.
3. There is a correlation between amount of sleep and number of calories burned. There is probably also causation. This is because there is likely anincreasein the number of calories burned with anincreasein the amount of sleep.

A traffic study determined that a larger city population indicates a longer commute time for drivers. What can we say from this information?

1. There isnocorrelation between commute time and city population.
2. There is a correlation between commute time and city population. However, there is no causation. This is because there is anincreasein the commute time with anincreasein the city population.
3. There is a correlation between commute time and city population. There may or may not be causation. Further studies would have to be done to determine this.

A company found that employees who start work earlier do not necessarily drink more or less coffee. Which statement is most likely true?

1. There isnocorrelation between start time and amount of coffee consumed.
2. There is a correlation between start time and amount of coffee consumed. There may or may not be causation. Further studies would have to be done to determine this.
3. There is a correlation between start time and amount of coffee consumed. However, there is no causation. This is because there is probably anincreasein the amount of coffee consumed with an earlier start time.