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Unformatted text preview: Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Total 12 Pts 12 Pts 12 Pts 10 Pts 13 Pts 25 Pts 17 Pts 101 Pts MATH 147 TEST TWO Spring 2004 March 8, 2004 Name: Section: DIRECTIONS: Show all work. Solutions with no work will receive NO credit. Neatness counts. All necessary tables are provided at the end of the test. Carry out all your calculations to at least two digits to the right of the decimal point. Part I True/False For questions 1 - 4 circle T for true and F for false. (2 points each) 1. T F If the events A and B are independent and the chance of each of these events is greater than 0, they must also be mutually exclusive . 2. T F Among all lines, the one that makes the smallest r.m.s. error in predicting y from x is the Regression line. 3. T F If the graph of averages happens to be a straight line, then it coincides with the regression line. 4. T F A deck of cards is shuffled. The chance that the top card is the jack of clubs or the bottom card is the jack of diamonds is 2/52. Part II Fill in the blank For the following questions, complete the sentence by filling in the blank. (2 points for each blank) 5. Suppose that men always married women who were exactly 8% shorter. The correlation between their heights would be . 6. Two variables have a correlation coefficient of r = 0 . 63. If each of the data items of the first variable are multiplied by 2, the numerical value of the resulting correlation coefficient is . 1 Part III Multiple Choice For the multiple choice questions, circle the answer which best completes the sentence or best answers the question. (3 points each) 7. In a regression setting for predicting y from x, (a) the R.M.S. error is generally smaller than the SD of y. (b) the R.M.S. error is generally smaller than the SD of x. (c) the R.M.S. error is generally larger than the SD of y. (d) the R.M.S. error is generally larger than the SD of x. (e) both (a) and (b) are true. 8. Heteroscedasticity in a regression setup (a) makes the R.M.S. error more reliable. (b) makes the prediction error more uniform....
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- Spring '07