Question

incorrect
your answer is incorrect.
the scatter plot shows the time spent studying, x, and the quiz score, y, for each of 23 students. use the scatter plot to answer the parts below. (note that you
can use the graphing tools to help you approximate the line.)
scratch area (not part of answer)
(a) write an approximate equation of the line of
best fit. round the coefficients to the nearest
hundredth.
( y = )
(b) using your equation from part (a), predict the
quiz score for a student who spent 50 minutes
studying. round your prediction to the nearest
hundredth.

Explanation:

Step1: Find two points on the line of best fit

Let's assume two points \((x_1,y_1)=(20,40)\) and \((x_2,y_2)=(60,80)\) (approximate from the scatter - plot).
The slope \(m=\frac{y_2 - y_1}{x_2 - x_1}=\frac{80 - 40}{60 - 20}=\frac{40}{40}=1\)
Using the point - slope form \(y - y_1=m(x - x_1)\), with \(m = 1\) and \((x_1,y_1)=(20,40)\)
\(y-40 = 1\times(x - 20)\)
\(y=x+20\)

Step2: Predict the quiz score for \(x = 30\)

Substitute \(x = 30\) into the equation \(y=x + 20\)
\(y=30+20=50\)

Answer:

(a) \(y=x + 20\)
(b) \(50\)