Chapter 4, Problem AP1.9CPT

To determine

To select the best option from the multiple choice question according to the given question.

Answer to Problem AP1.9CPT

Option (d) is correct.

Explanation of Solution

Given: A consistent amount of powder is dispensed each night,

Since a consistent amount is dispensed each night, the amount of powder used should increase as the number of days increase and thus there is a positive correlation between the number of days and amount of powder used.

Since the amount of powder left in the box is the initial amount of powder in the box decreased by the amount of powder used increases and thus there should be a perfect negative correlation between the amount of powder used and the amount of powder left.

Since there is a positive correlation between number of days and the amount of powder used and since there is negative correlation between amount of powder used and the amount of powder left, we expect a negative correlation between number of days and amount of powder left.

From this we note that II and III are true. So, the option (d) is the correct option.