Interpret Regression

A person travels by car.  They record their miles driven in a data table.  Calculate the linear regression equation of this data.

• y = 61.93x - 1.79

• y = -1.79x + 61.93

• y = 0.016x + 0.03

• y = 0.03x + 0.016

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books.  Use the graph to estimate the residual for the book with 15 chapters and 130 pages. (What is the vertical distance between the line and the point?)

• 20 pages

• -20 pages

• -5 pages

• 5 pages

Interpret the residual $5

• $5 is as expected

• $5 below expected

• $5 above expected

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books.  Estimate the residual for the book with 17 chapters and 170 pages.

• 10 pages

• -10 pages

• 0 pages

• -17 pages

Interpret the residual -50 miles

• 50 miles as expected

• 50 miles below expected

• 50 miles above expected

James is studying how temperature affects the drying time of concrete. interpret the slope.

• The slope of -0.29 indicates that for each 1 degree increase in temperature, the drying time decreases by 0.29 units.

• The slope of -0.29 suggests that a decrease in temperature leads to a decrease in drying time by 0.29 units.

• The slope of -0.29 indicates that the drying time is constant regardless of temperature changes.

• The slope of -0.29 means that for each 1 degree increase in temperature, the drying time increases by 0.29 units.

A perfectly negative correlation 

• implies a coefficient of determination of –1.0. 

• means that there must be a slope of –1.0.

• says that for every one additional unit of the variable on the x–axis, the variable on the y–axismust move down one additional unit.

• means that the r–value is is exactly 1.0. 

Some data were collected on the weight of a male white laboratory rat for the first 25 weeks after its birth. The linear regression equation is:
Weight = 100 + 40(Time).
Which is the best description of the slope for this regression equation in context of the problem?

• The slope of the line of regression is the time since birth of the rate. It demonstrates the predicted weight of a laboratory rate after so many months since birth.

• The slope is 40 grams/week which means the mouse gains about 40 grams per week after birth.

• The slope is 40 and it means for every increase in weeks the graph will increase. 

• The slope is 40, which tells us the line increases. 

Which is the best description of the y - intercept for the linear regression equation of the rats: Weight = 100 + 40(Time)?

• The y-intercept is 100, which means the rat is predicted to weigh 100 grams at birth. 

• The y-intercept is 100, which is where the graph crosses the y-axis. 

• 100 is where the data starts on the y-axis. 

• The y-intercept is 100, which means at a weight of 0, the rat will take 100 seconds.

What is the value of the correlation coefficient, r?

• 0.921

• -0.921

• 0.957

• -0.957