The following table shows the number of hours a cleaning company spends cleaning apartments. time (hours) 1 2 3 4 apartments cleaned 3 6 9 12 the relationship is . the relationship represents a . the rate of change represents .

First, plot the points in a graph to see the general trend. The independent variable is time. I used MS Excel to plot the points in a graph, as shown in the attached picture.

1. The relationship is linear as shown in the general trend.
2. The relationship presents that as time increases, the number of apartments cleaned also increases. The two variables are directly proportional.
3. The rate of change represents the slope of the line. Choose any two points and find the slope. 

m = (6-3)/(2-1) = 3 apartments cleaned/hour