q3_2 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 q3_2 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Provide an appropriate response. 1) The relationship between the number of games won by a minor league baseball team and the average attendance at their home games is analyzed. A regression to predict the average attendance from the number of games won has an r = Interpret this statistic. A) Positive, fairly strong linear relationship % of the variation in average attendance is B) Positive, fairly strong linear relationship. 73% of the variation in average attendance is C) Positive, weak linear relationship. 7.29% of the variation in average attendance is explained by the number of games won. D) No association E) Negative, fairly strong linear relationship % of the variation in average attendance is 2) A random sample of records of electricity usage of homes gives the amount of electricity used in July and size (in square feet) of 135 homes. A regression was performed to predict the amount of electricity used (in kilowatt-hours) based on size. The residuals plot indicated that a linear model is appropriate. Do you think the slope is positive or negative? Why? A) Positive. Larger homes should use more electricity. B) Negative. Larger homes should use less electricity. C) Negative. Smaller homes should use less electricity. D) Positive. More square feet indicates more houses. E) Positive. The larger the number of houses the more electricity used. 3) Would you expect the following pair of variables measured for 200 individuals aged to have a positive association, negative association, or no association: amount of time spent exercising per week; height? A) negative association B) positive association C) no association 4) Would you expect the following pair of variables measured for 200 individuals aged to have a positive association, negative association, or no association: age of vehicle; mileage for vehicle? A) positive association B) no association C) negative association 1) 2) 3) 4) Select the most appropriate answer. 5) If a positive association exists between two quantitative variables, 5) A) none of these. B) the movement of x does not affect the movement of y. C) y tends to increase as x decreases. D) y tends to decrease as x increases. E) y tends to decrease as x decreases. 6) In a negative association between two quantitative variables, 6) A) y tends to increase as x increases. B) y tends to increase as x decreases. C) y tends to decrease as x decreases. D) the movement of x does not affect the movement of y. E) none of these. 1

2 Determine the type of association apparent in the following scatterplot. 7) 7) A) Linear association, moderately strong association B) Positive association, moderately strong association C) Positive association, linear association D) Linear association, very strong association E) Positive association, linear association, very strong association 8) 8) A) Positive association, moderately strong association B) Little or no association C) Negative association, linear association D) Positive association, linear association E) Negative association, moderately strong association 2

3 9) 9) A) Positive association, moderately strong association B) Linear association C) Positive association, moderately strong association, linear association D) Linear association, moderately strong association E) Positive association 10) 10) A) Little or no association B) Moderately strong association, negative association C) Negative association, linear association D) Linear association E) Linear association, moderately strong association Answer true or false. 11) A scatterplot is a graphical display for two quantitative variables. 11) 3

4 Provide an appropriate response. 12) The correlation between the total box office receipts of the Oscar winner for best picture and the total number of Oscar nominations won is 0.69 for the best picture winners from 1990 to 2006 ( Assuming that the association is linear, describe the association. A) Weak linear association in a negative direction B) Strong linear association in a positive direction C) Weak linear association in a positive direction D) Strong linear association in a negative direction E) No evidence of association 13) Given the length of a person's femur, x, and the length of a their humerus, y, would you expect a positive correlation, a negative correlation, or no correlation? A) no correlation B) positive correlation C) negative correlation 14) For the 14 teams in baseball s American league, the correlation with number of wins in the 2007 regular season is 0.51 for shutouts, 0.61 for hits made, -.70 for runs allowed and for homeruns allowed. (mlb.mlb.com/stats/) Which variable has the strongest linear association with number of wins? A) homeruns allowed B) hits made C) runs allowed D) shutouts 15) For the 14 teams in baseball s American league, the correlation with number of wins in the 2007 regular season is 0.51 for shutouts, 0.61 for hits made, -.70 for runs allowed and for homeruns allowed. Which variable has the weakest linear association with number of wins? A) homeruns allowed B) shutouts C) hits made D) runs allowed 12) 13) 14) 15) Answer true or false. 16) The closer r is to 0, the weaker is the linear association between the variables. 16) 17) The value of the correlation is always between 0 and 1. 17) A) True B) False 18) If the absolute value of the correlation is approximately one, then the points lie close to a line that slopes upward or downward. 18) Select the most appropriate answer. 19) The correlation between two variables x and y 19) A) None of these. B) does not depend on the units of measurement of y or x. C) depends on the units of measurement of x. D) depends on the units of measurement of y. E) depends on the units of measurement of y and x. 4

5 20) If the correlation is approximately zero, then one can conclude 20) A) None of these. B) that there is a linear relationship between x and y. C) that there is no relationship between x and y. D) that there is a relationship between x and y. E) that there is no linear relationship between x and y. 21) Which of the following is not a property of r? 21) A) r measures the strength of any kind of relationship between x and y. B) r does not depend on which variable is treated as the response variable. C) The closer r is to zero, the weaker the linear relationship between x and y. D) r does not depend on the units of y or x. E) r is always between -1 and 1. 5