Regression Correlation

Estimate the correlation coefficient.

• r=0

• r=-1

• r=1

• r=2

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

If Joe worked 30 hours, how much is he expected to earn?

• $600

• $200

• $1000

• $800

The table shown is comparing a person's foot length to their height in cm. Calculate the regression equation

• yhat = 25.05x + 5.57

• yhat = 5.57x + 25.05

• yhat = -5.57x + 25.05

• yhat = 5.57x - 25.05

The chart below tracts starting salaries for health care workers since the year 2000. Using linear regression, find the equation of best fit. Round decimals to 3 places.

• yhat = 27541.812 + 839.721x 

• yhat = -839.721 + 27541.812x

• yhat = 839.721 + 27541.812x

• yhat = -27541.812 + 839.721x 

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.

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

• yhat = 28.93 + 1.155x

• height = 28.39(foot length) + 1.155

• yhat = 1.878 + 117.99x

• height = 117.99 + 1.878(foot length)

What is the correlation value?

• .209

• .457

• .13

• .361

Interpret the slope of the Least Squares Line Equation.

• Income increases by 31.45 with each additional 2 hours worked.

• Income increases by 31.45

• As hours increases by one, income will increase by 31.45.

• As hours increases by one, income will decrease by 242.3.