STAT 200 QUIZ 1 Instructor: Dr. Jing Gao NAME__________________________________ Spring 2016 INSTRUCTIONS The quiz is worth 40 points total. The quiz covers week 1 and week 2 materials. The quiz has two portions: Multiple Choice (8 problems, 16 points). Show work/explanation as appropriate. Short Answer (3 problems, 24 points) Show work. The quiz is open book and open notes. This means that you may refer to your textbook, notes, and online course materials, but you must work independently and may not consult anyone. You may take as much time as you wish, provided you turn in your quiz via LEO by 11:59 pm EDT on Sunday, March 13, 2016. With the quiz submission, please include the sentence, "I have completed this assignment myself, working independently and not consulting anyone except the instructor.\" MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1. (2 points) In the graph, there are two distrubitions: A and B From the graph, we can tell (check all that apply) A. The mean of distribution A> the mean of distribution B B. The mean of distribution A < the mean of distribution B C. The standard deviation of distribution A> the standard deviation of distribution B D. The standard deviation of distribution A= the standard deviation of distribution B 2. (2 points) For the following histogram of test scores, The majority of scores came between______ A. 39.5 and 49.5 B. 89.5 and 90.5 C. 159.5 and 169.5 D. 79.5 and 89.5 3. (2 points) Listed below are the amounts of time in months that the employees of a restaurant have been working at the restaurant. Find the median. 12 4 6 8.5 12 16 17 32 53 85 99 123 140 167 A. 24.5 months B. 58.7 months C. 17 months D. 32 months 4. (2 points) A Biased sample is one that ________ A. Is too small B. Will always lead to a wrong conclusion C. Will likely have certain groups from the population over-represented or under-represented due only to systematic sampling factors D. Will likely have certain groups from the population over-represented or under-represented due only to chance factors 5. (2 points) The students in John's math class took the Scholastic Aptitude Test. Their math scores are shown below. Find the mean score. 538 515 352 358 502 356 359 653 480 492 A. 460.5 B. 459.7 C. 450.5 D. 441.7 6. (2 points) The frequency distribution below summarize the home sale prices in a city for a specific month. Determine the width of each class. A. 28 B. 29 C. 30 D. 31 7. (2 points) The heights of a group of professional basketball players are summarized in the frequency distribution below. Find the mean height. . A. 78.2 in. B. 76.4 in. C. 74.4 in. D. 13.2 in. 8. (2 points) Listed below are the lengths in inches of each snake in the Atlanta Zoo's reptile house. Find the mode. 9 15 78 13 16 101 19 10 14 17 102 A. 17 inches B. 13.9 inches C. 78 inches D. no mode SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Express percents as decimals. Round dollar amounts to the nearest cent. 9. There are 31 participants in a special high-adventure camp. Following is a list of the age of the participants. 16, 18, 13, 24, 17, 17, 18, 14, 14, 16, 14, 20, 22, 21, 15 11, 13, 26, 27, 13, 16, 17, 17, 14, 19, 15, 17, 16, 19, 19, 28 a. (4 points) Prepare a frequency distribution of the participants' ages with a class width of 2, and another with class width of 5. b. (4 points) Construct a histogram of the participants' age with a class width of 2 and another with a class width of 5. 10. I have a collection of 5 ancient gold coins. Their weights, in ounces, are 23.1, 18.6, 33.5, 12.4, and 27.1. a. (2 point) What is the mean weight of my ancient gold coins? b. (2 point) How do you consider this collection, a population or a sample? Why? c. (4 points) What is the variance and standard deviation in weight of my coin collection? 11. Below is a summary of test score in two sections. The questions and possible maximum scores are different in these two sections. We notice that Student A4 in Section A and Student B2 in Section B have the same numerical score. Test A Student Score Test B Student Score A1 70 B1 15 A2 42 B2 61 A3 53 B3 48 A4 61 B4 90 A5 22 B5 85 A6 87 B6 73 A7 59 B7 48 ----- ------ B8 39 a. (5 points) How do these two students stand relative to their own classes according to their z scores? b. (3 points) Which student performed better? Explain your answer based on their z scores