MATH 225N Week 8 Assignment Predictions Using Linear
Regression
Make predictions using a line of best fit
Question
The table shows data collected on the relationship between the time spent studying per day and
the time spent reading per day. The line of best fit for the data is yˆ=0.16x+36.2. Assume the line
of best fit is significant and there is a strong linear relationship between the variables.
Studying (Minutes) 50,70,90,110 Reading (Minutes) 44,48,50,54
(a) According to the line of best fit, what would be the predicted number of minutes spent
reading for someone who spent 67 minutes studying? Round your answer to two decimal
places.
CORRECT ANSWER: 46.92.
Great work! That's correct.
Substitute 67 for x into the line of best fit to estimate the number of minutes spent reading for
someone who spent 67 minutes studying:
yˆ=0.16(67)+36.2=46.92.
(b) Is it reasonable to use this line of best fit to make the above prediction?
CORRECT ANSWER:
The estimate, a predicted time of 46.92 minutes, is both reliable and reasonable. The data in the
table only includes studying times between 50 and 110 minutes, so the line of best fit gives
reliable and reasonable predictions for values of x between 50 and 110. Since 67 is between
these values, the estimate is both reliable and reasonable.
Yes that's right. Keep it up!
Regression
Make predictions using a line of best fit
Question
The table shows data collected on the relationship between the time spent studying per day and
the time spent reading per day. The line of best fit for the data is yˆ=0.16x+36.2. Assume the line
of best fit is significant and there is a strong linear relationship between the variables.
Studying (Minutes) 50,70,90,110 Reading (Minutes) 44,48,50,54
(a) According to the line of best fit, what would be the predicted number of minutes spent
reading for someone who spent 67 minutes studying? Round your answer to two decimal
places.
CORRECT ANSWER: 46.92.
Great work! That's correct.
Substitute 67 for x into the line of best fit to estimate the number of minutes spent reading for
someone who spent 67 minutes studying:
yˆ=0.16(67)+36.2=46.92.
(b) Is it reasonable to use this line of best fit to make the above prediction?
CORRECT ANSWER:
The estimate, a predicted time of 46.92 minutes, is both reliable and reasonable. The data in the
table only includes studying times between 50 and 110 minutes, so the line of best fit gives
reliable and reasonable predictions for values of x between 50 and 110. Since 67 is between
these values, the estimate is both reliable and reasonable.
Yes that's right. Keep it up!
