AP Statistics Linear Regression

Which of the following statements is not true of the correlation r between the lengths in inches and weights in pounds of a sample of brook trout?

• r must take a value between -1 and 1.
• r is measured in inches.
• If longer trout tend to also be heavier, then r>0.
• r would not change if we measured the lengths of the trout in centimeters instead of inches.

Tags

CCSS.HSS.ID.C.8

CCSS.HSS.ID.C.9

Write the linear regression equation for the data set foot length (x) and height (y).

• ŷ = 28.39 + 1.155x

• ŷ = 28.39x + 1.155

• ŷ = 1.878 + 117.99x

• ŷ = 117.99 + 1.878x

What does r² stand for?

• correlation coefficient- measures strength and direction of linear association between x and y

• coefficient of determination- percent of the variation of y explained by the LSRL

• slope of the LSRL for a sample

• slope of the LSRL for a population

For the past two-hundred years population per square feet in a northwest suburb can be modeled using the exponential equation . The scatter plot of the data is shown below.

Which of the following statements is true?

• If an attempt is made at fitting a straight line to the original data, the corresponding residual plot would be approximately linear.

• If an attempt is made at fitting a straight line to the original data, the corresponding residual plot would not appear random.

What is the correlation?

• Negative correlation

• No correlation

• Positive correlation

Which is TRUE?
I.  Random scatter in the residuals indicates a linear model.
II.  If two variables are very strongly associated, then the correlation between them will be near 1 or -1.
III.  Changing the units of measurement for x or y changes the correlation coefficient.

• I only
• II only
• I and II only
• I, II and III

Tags

CCSS.HSS.ID.C.8

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.9

What should a residual plot look like?

• Distinct Pattern
• Curve
• Random with no pattern
• A few clumps

How do you calculate a residual?

• Observed - Predicted
• Predicted - Observed

After performing analyses on a set of data, Mrs. Bindemann examined the scatter plot of the residual values for each analysis. Which scatter plot indicated the best linear fit for the data?

• A

• B

• C

Shown is a residual plot. Would a linear regression model of the data be most appropriate?

• YES
• NO

Tags

CCSS.HSS.ID.B.6