Chapter 12 Review

What is the regression equation?

• y = intercept + slope*x

• x = intercept + slope*y

• y = slope*intercept + x

• y = intercept*x = slope

Which value represents the slope in the following equation:
 $y\ =\ b\ +ax$  

• y

• a

• x

• b

When the slope is negative, for every 1 unit increase in X, we predict that Y decreases by the absolute value of the slope

• True

• False

If the correlation coefficient is less than zero, x and y are negatively related.

• True

• False

The dependent variable is noted as x

• True

• False

What are the hypotheses for testing a positive linear relationship?

• Ho:  $\beta\ =\ 0$  
  Ha: $\beta\ <\ 0$  

• Ho:  $\beta\ \ne\ 0$  
  Ha: $\beta\ =\ 0$  

• Ha: $\beta\ \ne\ 0$  
  Ho:  $\beta\ \ge\ 0$  
  
  

• Ho:  $\beta\ =\ 0$  
  Ha:  $\beta\ >0$  
  
  

Data was collected on the weight of a male  laboratory rat for the first 25 weeks after its birth. The linear regression equation is 
y= 40x+100, where x is number of weeks and y is weight in grams. 
What does the y-intercept mean in context of the problem?

• The predicted weight of the rat in year 0. 
• The predicted weight of the rat at birth. 
• The current weight of the rat. 
• The average increase in the rat's weight. 

Tags

CCSS.HSS.ID.C.7

What does the Y intercept (b0) represent?

• The predicted value of Y when X=0

• The estimated change in average Y per unit change in X

• The predicted value of Y

• The variation around the line of regression

What does the standard error of the estimate measure?

• The total variation of the Y variable

• The typical error between predicted and observed values of the dependent variable

• The explained variation

• The variation of the X variable

What information is contained in the coefficient of determination (also known as r-squared)?

• The coefficient of correlation is larger than one

• Whether r has any significance

• We should not partition the total variation

• The proportion of total variation in Y that is explained by X by the linear model