The graph shows the number of gallons in a wading pool that is being drained. Using the points (1,160) and (3,80) as (x1,y1) and (x2,y2) , what is the rate of change in the number of gallons in the pool after each hour has passed?

Question

(1 point)
Responses

40 gal./hr.
40 gal./hr.

−140 gal./hr.
negative Start Fraction 1 over 40 End Fraction gal./hr.

140 gal./hr.
Start Fraction 1 over 40 End Fraction gal./hr.

−40 gal./hr.
negative 40 gal./hr.

Answer 1

The rate of change can be calculated using the formula:

Rate of change = (y2 - y1) / (x2 - x1)

Plugging in the values:

Rate of change = (80 - 160) / (3 - 1)
Rate of change = (-80) / 2
Rate of change = -40

Therefore, the rate of change in the number of gallons in the pool after each hour has passed is -40 gal./hr.