Elizabeth A. answered 11/22/19
Patient and Energetic Ivy League Math and Chemistry Tutor
I think this question is asking you to fit a line for the points (20, 67) and (40, 87), come up with the equation for this line and then use the equation to predict the score when time spent is 35 minutes.
Independent variable = time studying = x
dependent variable = score received = y
Calculate slope = m = Δy/Δx = (y2 -y1)/(x2 - x1) = (87 - 67)/(40 - 20) = 20/20 = 1
slope intercept form y = mx + b
y = (1)x + b
plug in (40, 87) to solve for b
87 = 40 + b
47 = b
Equation is
y = x + 47
For 35 minutes studying:
y = 35 + 47 = 82 = score when studying 35 minutes