Mr. Rogers  AP Statistics Objectives

AP Statistics Practice Test Regression Chapter 3  
1  )  When we say that a regression line explains a fraction of the variation in the ydata, where is the variation measured from? ybar 
2  )  Bob looks at a regression analysis with an rsquare of 0.20, a slope of .00012, and an intercept of 12, and concludes there is definitely no relationship between the variables. Is this a proper conclusion? Explain. There could be a nonlinear association 
3  )  Suppose the slope of a regression line is 7 and r = 0.50. If 3 is added to each explanatory (x) and response (y) data point, what will the new slope and r be? No change 
4 
)  Suppose the slope of a regression line is 7 and r =.50. If 3 is added only to each explanatory (x) data point data point, what will the new slope and r be? No change 
5  )  If the slope of a regression line is 5 and each explanatory (x) and response (y) data point is multiplied by .06 what is the new slope and r ? No change 
6 
)  If the slope of a regression line is 5 and each response (y) data point is multiplied by 0.06 what is the new slope and r ? 0.3, no change 
Use the following data for 7 thru 12: xbar =10; Yhat = 40 x 20; r = .80; Range of xdata used for regression analysis = 0 to 20. x represents pounds of fertilizer and y represents bushels of corn,  
7  )  Find: ybar: 380, slope; intercept; 20, % of the variation in the ydata explained by the regression equation: 64% 
8  )  If x = 6 y = 220 
9  )  If x is raised by 10 what is the increase in y ? 400 
10  )  If x represents pounds of fertilizer and y represents bushels of corn, how many bushels of corn will be harvested if no fertilizer is applied? No corn 
11  )  Ken the farmer looks at the regression analysis and decides to apply 700 lbs. of fertilizer to his garden in order to get a really big corn crop. What is wrong with his analysis? Extrapolation 
12  )  You as a high priced consultant look at the residual plot for the above regression and can detect no pattern in the residuals. How do you interpret this? The regression equation is appropriate 
13  )  When r = 0 is there definitely no relationship between the variables? No could be nonlinear relationship 
14  )  How is the regression line represented on a residual plot? Essentially, the horizontal axis of the residual plot represents the regression line. If all the residuals were zero, all the data points would be on the regression line in a scatter plot and all the residuals would be on the horizontal axis of the residual plot. 
15  )  The sum of the residuals for least squares regression analysis is always ___________. Zero 
16  )  A researcher wants to find the relationship between mass and length for rattle snakes. She performs regression and correlation analysis with mass in units of kilograms and length in meters. She decides to rerun the analysis using pounds and inches. What parts of the regression and correlation analysis output will change? rsquare the same, slope and intercept both will change 
SAM TeamSouthside High School's STEM and Computer Science extracurricular club (Mr. Rogers Sponsor) Mr. Rogers Information for Teachers Mr. Rogers Science Fair Information Check out other web sites created by Mr. R: Check out Articles by Mr. Rogers: 

Mr. Rogers Home  Common Sylabus  AP Comp Sci I  AP Comp Sci II  AP Physics Mech  AP Physics E&M  AP Statistics  Honors PhysicsIB Design Tech  Southside