To check this is entered correctly on your calculator, press [stat], go to CALC, and select "2:2-Var Stats". Run this on your two lists. When you scroll down the list, you should see Σxy=89020
Enter the data into your calculator and obtain a linear equation of best fit using the linear regression feature. Type the equation here, in the form y=mx+b
. If necessary, round the values of m
and b
to three decimal places.
Based on your regression equation, what score would you predict for a student who has studied for 1 hour and 30 minutes? Round your answer to a whole number of points.
points
Based on your regression equation, how much time should a "typical" student spend studying if they wanted to score at least 90 points on the exam? Round your answer up to the next full minute.
minutes
The linear equation of best fit obtained from the calculator is:
y = 5.077x + 19.391
To predict the score for a student who has studied for 1 hour and 30 minutes, we first convert this time into decimal hours:
1 hour and 30 minutes = 1.5 hours
Now, substitute x = 1.5 into the equation:
y = 5.077 * 1.5 + 19.391
y = 27.841 + 19.391
y = 47.232
So, the predicted score for a student who has studied for 1 hour and 30 minutes is 47 points.
To find out how much time a "typical" student should spend studying to score at least 90 points on the exam, we rearrange the equation:
90 = 5.077x + 19.391
70 = 5.077x
x = 13.791
So, a "typical" student should spend at least 14 hours studying to score 90 points on the exam.