lukes math teacher plots student grades on their weekly quizzes against the number of hours they say they…
lukes math teacher plots student grades on their weekly quizzes against the number of hours they say they study on the pair of coordinate axes and then draws the line of best fit. based on the line of best fit, how much time should someone study to expect a quiz score of 83?
Answer
Explanation:
Step1: Find slope of line
Use points $(0,56)$ and $(4,80)$: $$m=\frac{80-56}{4-0}=\frac{24}{4}=6$$
Step2: Write line equation
Slope-intercept form $y=mx+b$, $b=56$: $$y=6x+56$$
Step3: Solve for $x$ when $y=83$
Substitute $y=83$, isolate $x$: $$83=6x+56$$ $$6x=83-56=27$$ $$x=\frac{27}{6}=4.5$$
Answer:
4.5 hours