At 1:00 the water level in a pool is 13 inches at 2:30 in the water level is 28 inches what is the rate of change

Let x = time, hours, from 1:00

Let y = water level, inches

Note that from 1:00 to 2:30, x = 2.5 - 1.0 = 1.5 hours.

The given data is

x: 0 1.5

y: 13 28.0

The change in x is 1.5 - 0 = 1.5 hours

he change in y is 28 - 13 = 15 inches

The rate of change is (15 inches) / (1.5 hours) = 10 inches/hour

Answer: 10 inches per hour