Interpreting Line of Best Fit

The scatter plot below shows the relationship between years of experience and points scored. The equation for the line of best fit is y = 0.6x + 4 What is the meaning of 4 in the equation?

• The equation predicts that zero years of experience will result in the points scored to be 4

• The equation predicts that zero years of experience will result in the points scored to be −4

• For each additional year of experience, the points scored tends to increase by 4

• For each additional point scored, the years of experience tends to increase by 4

Which of the following lines represents the line of best fit for the scatter plot?

• A

• B

• C

• D

The equation of this line is y = -2.2x + 12.4. Interpret the meaning of the slope of the line of best fit.

• for each hour of practice, you will make 12.4 mistakes

• without practicing, you would expect to make 12.4 mistakes

• for each hour of practice, the number of mistakes decreases by 2.2

• for each hour of practice, the number of mistakes increases by 2.2

The equation of this line is y = -2.2x + 12.4. Interpret the meaning of the y-intercept of the line of best fit.

• for each hour of practice, you will make 12.4 mistakes

• without practicing, you would expect to make 12.4 mistakes

• for each hour of practice, the number of mistakes decreases by 2.2

• for each hour of practice, the number of mistakes increases by 2.2

Interpret the meaning of the slope of the line of best fit.

• without studying, the expected test score would be 55.2%

• for every hour studied, test score decreases by 1.4%

• for every hour studied, test score increases by 1.4%

• without studying, the test score would be expected to be 1.4%

Interpret the meaning of the y-intercept of the line of best fit.

• without studying, the expected test score would be 55.2%

• for every hour studied, test score decreases by 1.4%

• for every hour studied, test score increases by 1.4%

• without studying, the test score would be expected to be 1.4%

The slope of this line is 1.33. This means that a student's test score will increase by 1.33 for every additional minute they study.

• True

• False

Which shows a line of best fit drawn correctly?

• 
• 
• 
• 

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books.  Use the trend line to predict how many chapters would be in a book with 140 pages. 

• 12 chapters

• 19 chapters

• 14 chapters

• 21 chapters

The equation of this line is y = -2.2x + 12.4. Using the equation of the line of best fit, how many mistakes would you expect to make after practicing for 3 hours?

• 5.4 mistakes

• 5.2 mistakes

• 6.4 mistakes

• 5.8 mistakes