147-sample3

147-sample3 - 1. In a regression setting for predicting y...

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1. In a regression setting for predicting y from x, the regression line and the SD line are the same a. if the correlation coefficient is 0. b. if the correlation coefficient is -1. c. if the SD of y-values equals the SD of the x-values. d. if the average of the y-values equals the average of the x-values. e. if both (c) and (d) hold true for the data. Answer (b) 2. If the correlation coefficient between two variables is zero (r = 0), then a. the scatter plot of the two variables shows no pattern whatsoever. b. none of the points on the scatter plot lie within 1 SD of the regression line. c. there is a tight clustering about the SD line. d. there is no linear association between the variables. e. all of the above statements are true. Answer (d) 3. The correlation coefficient between two variables a. is affected by interchanging the variables. b. is affected by multiplying all of the values of one variable by the same positive number. c. is affected by adding the same number to all of the values of one variable. d. is affected by multiplying all of the values of one variable by the same negative number. e. always lies between 0 and 1. Answer (d) 4. In a regression setting for predicting y from x, a. the regression line is just a smoothed version of the graph of averages. b. the regression line passes through the point of averages. c. the r.m.s. error measures the deviation of the scatter diagram's points from the SD line. d. both (a) and (b) are true. e. all of the above statements are true. Answer (d) 5. If A and B are independent events, a. the chance that A happens given that B happened is the same as the chance that B happens. b. the two events A and B must be mutually exclusive.

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c. the chance of A and B both happening is equal to the chance of A plus the chance of B. d. both (b) and (c) are true. e. none of the above statements are true. Answer (e) 6. For two mutually exclusive events, a. the probability that at least one of the events occurs is the sum of the individual probabilities. b.
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This note was uploaded on 05/27/2008 for the course MATH 147 taught by Professor Klimko during the Fall '07 term at Binghamton University.

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147-sample3 - 1. In a regression setting for predicting y...

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