AP Stats
Least Squares Regression Practice
1.
2.
Name: ___________________________
Period: ____
Freshmen at Webb Schools go on a backpacking trip at the start of each school year. Students are divided into
hiking groups of size 8 by selecting names from a hat. Prior to departure, each student’s weight and backpack
weight are measured (both in pounds). Here are the data from one hiking group in a recent year:
a)
Identify the explanatory & response variables for this situation.
b)
Create a scatterplot for this data using your graphing calculator. Interpret the scatterplot.
c)
Use the summary statistics below to find the equation of the least squares regression line for the above
set of data (r = 0.7947). Interpret the slope & y-intercept in context.
A study recorded the number of beers consumed and blood alcohol content (BAC) for 16 students.
a)
Identify the explanatory & response variables for this situation.
b)
Use the summary statistics below to find the equation of the least squares regression line for the above
set of data (r = 0.8944). Interpret the slope and y-intercept in context.
3.
Use the computer printouts below to write the linear regression model.
a)
4.
b)
Professor Moore swims 2000 yards regularly in a vain attempt to undo middle age. Here are his times (in
minutes) and his pulse rate after swimming (in beats per minute) for 23 session in the pool.
a)
Identify the explanatory and response variable.
b)
Create a scatterplot (sketch below) and comment on what it shows about the data.
c)
Use your calculator to find the least squares regression model. Interpret the slope & y-intercept in
context.
d)
What was the correlation? Interpret this value.
e)
Use the linear model created in part c to estimate Professor Moore’s pulse if he swam 2000 yards in
34.50 minutes. Is this interpolation or extrapolation? Explain.
f)
Use the linear model created in part c to estimate Professor Moore’s pulse if he swam 2000 yards in 31
minutes. Is this interpolation or extrapolation? Explain.