Ch04_Sect04_Keller MS_AISE TB

# Ch04_Sect04_Keller MS_AISE TB - CHAPTER 4 SECTION 4:...

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CHAPTER 4 SECTION 4: NUMERICAL DESCRIPTIVE TECHNIQUES MULTIPLE CHOICE 216. Assuming a linear relationship between X and Y , if the coefficient of correlation ( r ) equals - 0.80, this means that: a. there is very weak correlation. b. the slope b 1 is = - 0.80. c. the value of X is always greater than the value of Y. d. None of these choices are true. ANS: B PTS: 1 REF: SECTION 4.4 217. The slope b 1 of the least squares line represents the: a. predicted value of Y when X = 0. b. estimated average change in Y per unit change in X. c. predicted value of Y. d. variation around the regression line. ANS: B PTS: 1 REF: SECTION 4.4 218. Generally speaking, if two variables are unrelated (as one increases, the other shows no pattern), the covariance will be: a. a large positive number. b. a large negative number. c. a positive or negative number close to zero. d. None of these choices. ANS: C PTS: 1 REF: SECTION 4.4 219. If the correlation coefficient r = 1.00, then all the observations must fall exactly on: a. a straight line with a slope that equals 1.00. b. a straight line with a negative slope. c. a straight line with a positive slope. d. a horizontal straight line with a zero slope. ANS: C PTS: 1 REF: SECTION 4.4 220. The Y -intercept, b 0 , of the least squares line represents the: a. estimated average value of Y when X = 0. b. estimated average change in Y per unit change in X. c. predicted value of Y. d. variation around the sample regression line. ANS: A PTS: 1 REF: SECTION 4.4 221. A perfect straight line sloping downward would produce a correlation coefficient equal to: a. +1.0 b. - 1.0 c. 0.0 d. Cannot tell from the information given. ANS: B PTS: 1 REF: SECTION 4.4 This edition is intended for use outside of the U.S. only, with content that may be different from the U.S. Edition. This may not be resold, copied, or distributed without the prior consent of the publisher.

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222. The least squares method minimizes which of the following sum of squares? a. b. c. d. All of these choices are true ANS: B PTS: 1 REF: SECTION 4.4 223. Which of the following is a property of r , the coefficient of correlation? a. r always lies between 0 and 1. b. r has no units. c. If you switch the values of X and Y , the sign of r changes. d. All of these choices are true. ANS: B PTS: 1 REF: SECTION 4.4 224. Which of the following is a property of the slope, b 1 ? a. The slope equals one if X and Y have the same variance. b. The slope has the same sign as r , the coefficient of correlation. c. The slope equals one if r equals one. d. All of these choices are true. ANS: B
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## This note was uploaded on 04/08/2012 for the course ADMS 2320 taught by Professor Rochon during the Spring '08 term at York University.

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Ch04_Sect04_Keller MS_AISE TB - CHAPTER 4 SECTION 4:...

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