Use the image to answer the 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.
Start Fraction 1 over 40 End Fraction gal./hr.
40 gal./hr.
40 gal./hr.
−40 gal./hr.
negative 40 gal./hr.
−140 gal./hr.
negative Start Fraction 1 over 40 End Fraction gal./hr.
Skip to navigation
To find the rate of change in the number of gallons in the pool after each hour has passed, we need to calculate the slope of the line segment between the two points (1,160) and (3,80).
The slope formula is given by:
slope = (y2 - y1)/(x2 - x1)
Using the coordinates (1,160) as (x1, y1) = (1,160) and (3,80) as (x2, y2) = (3,80), we can substitute the values into the formula:
slope = (80 - 160)/(3 - 1)
Simplifying the expression we get:
slope = (-80)/2
slope = -40
Therefore, the rate of change in the number of gallons in the pool after each hour has passed is -40 gallons per hour. The correct answer is: negative 40 gal./hr.