Question

question
naomis 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, what quiz score should someone who studied 6 hours expect?
answer attempt 1 out of 2
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Explanation:

Step1: Find the slope of the line

Use two - point formula $m=\frac{y_2 - y_1}{x_2 - x_1}$. Let $(x_1,y_1)=(2,70)$ and $(x_2,y_2)=(4,82)$. Then $m=\frac{82 - 70}{4 - 2}=\frac{12}{2}=6$.

Step2: Find the y - intercept

The line passes through $(0,58)$, so the y - intercept $b = 58$.

Step3: Write the equation of the line

The equation of a line is $y=mx + b$. Substituting $m = 6$ and $b = 58$, we get $y=6x+58$.

Step4: Predict the score for 6 hours of study

Substitute $x = 6$ into the equation $y=6x+58$. Then $y=6\times6 + 58=36+58 = 94$.

Answer:

94