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Unformatted text preview: Answers: bacba cdcca dcadb aceed deeee bbbee MATH201 Fall 2008 Final Exam a Name: ____________________________________________________________ Lab Section :_____________ Instructions: 1. Do not start until instructed to do so. 2. If you brought a cell phone by mistake, turn it off and place it under your seat. You may NOT use it as a calculator. 3. You may use a calculator (NOT a cell phone calculator). 4. Code your Last Name in the Last Name space, your First Name in the First Name space, and your 5- or 9-Digit UDel Student ID Number in the Student ID Number space on your scansheet and fill in the bubbles. 5. DO NOT put any part of your Social Security Number on your scansheet. 6. Choose the best answer to each question. 7. Use = 0.05, unless otherwise indicated. 1 1. The Third international Mathematics and Science Study (TIMSS) in 1999 examined eighth- graders proficiency in math and science. The mean geometry score for the sample of 60 eighth- grade students in the United States was 473 with a standard error of 4.4. The 95% confidence interval for the mean geometry score for all eighth-grade students in the United States is (464.4, 481.6). Which of these is true? a. There is a 95% chance that the mean geometry score for all eighth-graders in the United States is 473. b. If we took many random samples of 60 eighth-graders in the United States, 95% of the confidence intervals would contain the mean geometry score for all eighth-graders in the United States. c. If we took many random samples of 60 eighth-graders in the United States, 95% of the sample means would be between 464.4 and 481.6. d. If we took many random samples of 60 eighth-graders in the United States, 95% of the confidence intervals would contain 473. e. If we took many random samples of 60 eighth-graders in the United States, 95% of the sample means would be equal to 473. 2. A certain adjustment to a machine will change the length of the parts it is making but will not affect the standard deviation. The length of the parts is normally distributed. After an adjustment, a random sample of 10 measurements is taken to determine the mean length of parts now produced. Descriptive statistics of the 10 measurements are given below. Calculate the 99% confidence interval estimate for the mean length of all parts now being produced by the machine. Descriptive Statistics: Length (mm) Variable N N* Mean SE Mean StDev Minimum Q1 Median Q3 Length (mm) 10 0 75.920 0.244 0.773 74.900 75.225 75.900 76.625 Variable Maximum Length (mm) 77.000 a. 75.92 3.25* 10 773 . b. 75.92 2.58*0.773 c. 75.92 2.33* 10 773 . d. 75.92 2.33*0.773 e. 75.92 2.82* 10 773 . We have a small sample size (< 30), we can assume a normally-distributed population of lengths, and , the population standard deviation is unknown, so we use a t-interval (9 df). If you don't divide by 2, you get e. Choices b, c, and d use a z-interval....
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This note was uploaded on 12/07/2011 for the course MISY 160 taught by Professor Universal during the Fall '08 term at University of Delaware.
- Fall '08