Answer:
First problem:
$3.75/3 papayas = $1.25/papaya
The slope of this line is 1.25 = 5/4.
The unit rate and the slope of the line represent the cost of each papaya.
Second problem:
The unit rate is 0.5 inch/week (1/2 inch per week).
The slope of the line that best represents the height of the plant is 1/2.
The unit rate and the slope of the line represent the rate of increase in the height of the plant per week.