AP Stats Chapters

The correlation (r) between high school students' height (in inches) and weight (in pounds) for a large sample of students is found to be 0.3. If the weight measurements are converted to kg, what will be the resulting correlation?

• 0.3

• 0.66

• -0.3

• 0.136

For a particular value of an explanatory variable, the residual is -0.7. Which of the following is a true statement?

• The regression line underestimates the actual response variable value at this point.

• The regression line overestimates the actual response variable value at this point.

• . A non-linear regression would provide a better fit.

Data is obtained for a large group of college students relating the time they spent writing an essay and the grade on the essay. The equation is grade = 30.18 + 6.49(time) with r = 0.724 What percentage of the variation in grades can be explained by looking at time spent on the essay?

• 52.4%

• 72.4%

• 27.6%

• 47.6%

Interpret the circled point on this relative cumulative frequency graph.

• 60% of Starbucks drinks have 30g of sugar.

• 60% of Starbucks drinks have 30g of sugar or more.

• 60% of Starbucks drinks have 30g of sugar or less

• None of these interpretations is correct.

Desiree is interested to see if students who consume more caffeine tend to study more as well. She randomly selects 20 students at her school and records their caffeine intake (mg) and the number of hours spent studying. What is the equation for the LSRL?

• Caffeine = 2.544 + 0.164(hours)

• Hours = 2.544 + 0.164(Caffeine)

• Caffeine = 0.164 + 2.544(hours)

• Hours = 0.164 + 2.544(Caffeine)

The linear regression equation is y = 61.93x - 1.79.  Use the equation to predict how far this person will travel after 10 hours of driving.

• 10 miles

• 617.5 miles

• 0.19 miles

• 500 miles

A restaurant sells pizza for the prices in the data table.  Calculate the linear regression equation of the data.

• y = 1.5x + 12

• y = 12x + 1.5

• y = 0.67x - 8

• y = -8x + 0.67

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 180 pages. 

• 12 chapters

• 15 chapters

• 18 chapters

• 21 chapters

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

Estimate the correlation coefficient for this scatterplot.

• r = 1.2

• r = 0.89

• r = 0

• r = -0.89