# mt2sol - GE331/IE 300 Analytic Methods For Uncertainty /...

This preview shows pages 1–4. Sign up to view the full content.

GE331/IE 300 Analytic Methods For Uncertainty / Analysis of Data Spring 2011 University of Illinois G. Koksal EXAM II Thursday, April 7, 7:00-8:30 pm Open textbook, lecture notes and/or cheat sheets. Calculators are allowed. NAME: Solution Key for Type A Please clearly PRINT your name in CAPITAL LETTERS. ITEM Questions Total PART 1 (30 points) 1 2 3 4 5 6 7 8 9 10 11 12 Answers PART II (75 points) 1 2 3 4 5 Scores Total

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Name: Solution Key 4.7.2011 GE331/IE300 EXAM 1 PART I (30 points) Choose the best answer to the following questions. Circle your answers on the questions and also write them on the table on the cover sheet . 1) (2.5 pts.) Suppose a sample of size n 1 is taken from a normal distribution the population mean of which is unknown and the population variance is . If we want to decrease the length of the 100(1-  % confidence interval X 1 n z  for the mean by half then we must take a sample of size n 2 given approximately by a) n 2 = ( 1 n 2 z  ) 2 b) n 2 =2 n 1 c) n 2 =n 1 /2 d) n 2 =4 n 1 Answer: d 1 2 1 2 / 2 2 / 4 ) ( 2 1 n n n z n z 2) (2.5 pts.) Let H 0 : = 0 , H 1 : . Let X be the mean of a random sample with large n. Then, a) As X gets closer to 0 , the corresponding p-value increases. b) If H 0 is rejected, then p-value of the test statistic is greater than . c) p-value increases as increases. d) If X = 0 , then p-value is 0.5. Answer: a 3) (2.5 pts.) n S X T / 0 0 A _____ such as T 0 is called ____ , and T 0 is simply a function of ____. a) Parameter, a test statistic, population. b) Test statistic, a parameter, population. c) Random variable, the critical value, samples. d) Parameter, the critical value, random variables. e) Random variable, a test statistic, samples.
Answer: e 4) (2.5 pts.) Suppose that you are testing a hypothesis on the variance of a normal distribution. Consider the following display: Test and CI for One Variance Null hypothesis Sigma-squared = 18 Alternative hypothesis Sigma-squared not = 18 95% Confidence Intervals CI for CI for Method StDev Variance Chi-Square (3.30, 8.76) (10.9, 76.8) Which of the following can be concluded based on this output? a) The p-value should be less than 0.05 b) The true 2 value cannot be more than 76.8 c) Reject that 2 =18 with 95% confidence d) Fail to reject that =4.2426 with 95% confidence Answer: d 5) (2.5 pts.) In a market research, customer representatives were selected based on their income levels and ages. Four groups were defined: low income-teenager, high income-teenager, low income-adult, high income-adult. In each group a certain proportion of customers were randomly selected. What type of sampling is this?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 01/26/2012 for the course IE IE 300 taught by Professor Zafarani during the Spring '09 term at University of Illinois, Urbana Champaign.

### Page1 / 9

mt2sol - GE331/IE 300 Analytic Methods For Uncertainty /...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online