Use the image to answer the question.

Question

A coordinate plane shows the x-axis, labeled as hours, ranging from 0 to 6 in increments of 1 and the y-axis, labeled as gallons, ranging from 0 to 240 in increments of 20. A line segment joins four plotted points. The coordinates of the plotted points are left parenthesis 0 comma 200 right parenthesis, left parenthesis 1 comma 160 right parenthesis, left parenthesis 3 comma 80 right parenthesis, and left parenthesis 5 comma 0 right parenthesis.

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?

(1 point)
Responses

−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.

40 gal./hr.

Answer 1

The rate of change in the number of gallons in the pool can be calculated using the formula:

(rate of change) = (change in gallons) / (change in hours)

Given the points (1,160) and (3,80):

Change in gallons = 80 - 160 = -80 gallons
Change in hours = 3 - 1 = 2 hours

So, the rate of change in the number of gallons in the pool after each hour is:
-80 gallons / 2 hours = -40 gallons/hour

Therefore, the rate of change in the number of gallons in the pool after each hour is -40 gallons per hour. The correct answer is -40 gal/hr.