25. Refer to Figure 2-16. Cups of coffee per day and the hours that someone can go without sleep appear to have
26. Refer to Figure 2-16. Taking cause and effect into account, which of the following interpretations would be most
reasonable regarding the relationship between coffee and hours without sleep?
The less coffee a person drinks per day, the more time he can go without sleep.
There is no relationship between how much coffee per day a person drinks and how long he can go without
sleep.
The more coffee a person drinks per day, the more time he can go without sleep.
The more coffee a person drinks per day, the less time he can go without sleep.
27. When two variables move in opposite directions, the curve relating them is
upward sloping, and we say the variables are positively related.
upward sloping, and we say the variables are negatively related.
downward sloping, and we say the variables are positively related.
downward sloping, and we say the variables are negatively related.
28. When two variables move in the same direction, the curve relating them is
upward sloping, and we say the variables are positively related.
upward sloping, and we say the variables are negatively related.