MATH 225N Week 8 Assignment Predictions Using Linear Regression
Make predictions using a line of best fit
Question
The table shows data collected
... [Show More] 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!
Make predictions using a line of best fit
Question
Michelle is studying the relationship between the hours worked (per week) and time spent reading (per day) and has collected the data shown in the table. The line of best fit for the data is yˆ=−0.79x+98.8. Assume the line of best fit is significant and there is a strong linear relationship between the variables.
Hours Worked (per week) 30,40,50,60 Minutes Reading (per day) 75,68,58,52
(a) According to the line of best fit, what would be the predicted number of minutes spent reading for a person who works 27 hours (per week)? Round your answer to two decimal places, as needed.
CORRECT ANSWER: 77.47
Correct! You nailed it. Substitute 27 for x into the line of best fit to estimate the number of minutes spent reading for a person who works 27 hours (per week):
yˆ=−0.79(27)+98.8=77.47.
(b) Is it reasonable to use this line of best fit to make the above prediction?
CORRECT ANSWER:
The estimate, a predicted time of 77.47 minutes, is unreliable but reasonable.
Perfect. Your hard work is paying off 😀.
The data in the table only includes the time worked between 30 and 60 hours, so the line of best fit gives reliable and reasonable predictions for values of x between 30 and 60. Since 27 is not between these values, the estimate is not reliable. However, 77.47 minutes is a reasonable time. [Show Less]