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.
40 gal./hr.
40 gal./hr.
140 gal./hr.
Start Fraction 1 over 40 End Fraction gal./hr.
−40 gal./hr.
To find the rate of change, we need to calculate the slope of the line passing through the two points (1,160) and (3,80).
Slope (m) = (y2 - y1) / (x2 - x1)
= (80 - 160) / (3 - 1)
= (-80) / 2
= -40
Therefore, the rate of change in the number of gallons in the pool after each hour has passed is 40 gal./hr.