Solving MCAS Open Response Questions By Lawrence Scandone
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What info have I been given? 1st $200 dollar expence for equipment. 2nd Rodney earns $40 dollars for each horse that he grooms. 3rd Profit is equal to his earnings for each horse groomed minus the initial expense.
What is the profit for grooming 15 horses? 1st Rodney earns $40 dollars for each horse groomed. 2nd He groomed 15 horses. 3rd So I multiply $40 x 15 which is $600. 4th Since profit = I – E { P = $600 - $200 } Profit = $400
Graph Title Title:________________________________
Label the X-axis Name:_______________________________
Label the Y- axis Name:
Plot the Profit for 0 to 7 horses X = # of horses Groomed (0 to 7) Y =Rodney’s profit Y 200 X 2 4 6 8 -200
1st ask yourself what m =__ 2nd ask yourself what b =__ Write the equation Y = mX + b 1st ask yourself what m =__ 2nd ask yourself what b =__
M stands for the slope It’s equal to the rise/ run or the rate of change which is $40.
B stands for the Y-intercept It’s where the graph crosses the y- axis or in this case a one time charge, which is the starting value.
Replace m and b You plug 40 in for m and you replace b with (- 200). Y = 40X – 200 is the equation
What does the X-intercept represent? Think about money! What is Rodney’s profit at the X-intercept? How many horses did he groom at the X-intercept Show and explain your answer for this point on the graph. What does it stand for in terms of Rodney’s business?