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 40 gal./hr. 40 gal./hr. 140 gal./hr. Start Fraction 1 over 40 End Fraction gal./hr. −40 gal./hr. negative 40 gal./hr. −140 gal./hr.
To find the rate of change, we need to find the slope of the line passing through the points (1,160) and (3,80). The slope is defined as the change in y divided by the change in x.
Change in y = 80 - 160 = -80
Change in x = 3 - 1 = 2
Slope = change in y / change in x
Slope = -80 / 2 = -40
Therefore, the rate of change in the number of gallons in the pool after each hour has passed is -40 gallons per hour.