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?
To find the rate of change, we need to calculate the slope of the line passing through the points (1, 160) and (3, 80).
The slope formula is given by:
slope = (y2 - y1) / (x2 - x1)
Plugging in the values:
slope = (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 gallons per hour.