MAT222-2007Fall - Fall 2007 M AT 2 22 F inal December 1 2 2...

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Fall, 2007 MAT 222 Final (December 12, 2007) Nanle: ______________________________________ ___ *************** 1. There are 7 problems and a total of 9 pages in this booklet. 2. Show all of your work and label your answers clearly. 3. If you use a table, state the table used: for example 1.887 (from Table A). 4. If you use a function on the TI 83 (or TI 89), write out the command you entered as well as the result: for example, 0.0668 (normalcdf (-10, -1.5, 0.1)). *************** 1 15 2 14 3 17 4 24 5 15 6 9 7 6 1
1. (15 pts) Students in a statistics class were asked the question: How many hours typically exercise in a week? The following summary statistics are obtained: (a) At the 5% level of significance, conduct a test to determine if the mean exercise differs for men and women. (b) Cheek if each of the following statements is true for the test in (a). Explain not. (i) We are assuming the population variances are equal for the two populations in study. (ii) "11" is an appropriate degrees of freedom. (iii) If MINITAB is used to analyze this data, the degrees of freedom could be number. (iv) If the alternative hypothesis is that males exercise more than females, the be significant at 0.05 level of significance. do you amount of why or why the a decimal test will 2
2. (14 pts) This Washington Post poll was conducted by telephone during October 4-8, 2007 for a random sample of 1,144 adults in the Commonwealth of Virginia. For the question, "Regardless of who you may support, which of the Democratic candidates do you think the best chance of getting elected president in November 2008?", the following summary results are obtained. I Candidate of choice Political Party Democrats Non Democrats H. Clinton B. Obama Others 328 76 100 324 130 186 Analyze the two-way table. State the hypotheses, calculate the X 2 statistic, degrees of free dom, P-value and your conclusion. has - 3
3. (17 pts) In the poll conducted for the 504 Democrats in the Commonwealth of Virginia, 49% of the respondents said that they would vote for Hillary Clinton if the 2008 Democratic presidential primary or caucus in their state were being held today. (a) Find a 99% confidence interval for the proportion of Democrats in the Commonwealth of Virginia who support Hillary Clinton. (b) Based on your confidence interval in (a), can you conclude that the proportion of Virginia Democrats who support Hillary Clinton is not significantly different from 0.5? Explain why or why not. (c) Do data provide good evidence that the proportion of supporters of Hillary Clinton in Virginia is significantly lower than 53% observed in a national survey conducted about a month ago? Find the P-value of the test and draw the conclusion at 0.01 level of significance. 4

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