This file is /conf/snippets/setheader.pg you can use it as a model for creating files which introduce each problem set.

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1 Stephanie Abuso AMS WeBWorK assignment number HW3 is due : 02/28/2014 at 10:30pm EST. The (* replace with url for the course home page *) for the course contains the syllabus, grading policy and other information. This file is /conf/snippets/setheader.pg you can use it as a model for creating files which introduce each problem set. The primary purpose of WeBWorK is to let you know that you are getting the correct answer or to alert you if you are making some kind of mistake. Usually you can attempt a problem as many times as you want before the due date. However, if you are having trouble figuring out your error, you should consult the book, or ask a fellow student, one of the TA s or your professor for help. Don t spend a lot of time guessing it s not very efficient or effective. Give 4 or 5 significant digits for (floating point) numerical answers. For most problems when entering numerical answers, you can if you wish enter elementary expressions such as 2 3 instead of 8, sin(3 pi/2)instead of -1, e (ln(2)) instead of 2, (2 +tan(3)) (4 sin(5)) 6 7/8 instead of , etc. Here s the list of the functions which WeBWorK understands. You can use the Feedback button on each problem page to send to the professors. 1. (1 pt) To conduct a door-to-door survey about crime victimization, a city official randomly selects 5 city blocks and surveys all the residents of these 5 city blocks. What type of sample is this? A. Systematic Random Sample B. Simple Random Sample C. Cluster Sample D. Multistage Sample E. Stratified Random Sample 2. (1 pt) Nine percent of the U.S. population has Type B blood. In a sample of 400 individuals from the U.S. population, 12.5 In this particular situation, the value of 9 A. parameter B. statistic What is the value of N, the population size? What is the sample in this situation? A. all U.S. senators B. randomly selected U.S. senators What is the value of n, the sample size? 4. (1 pt) As part of a study on the effect of forest fragmentation on the decline of the songbird population, a team of researchers needs to gather information on nest predation. A large forest area is divided up into N=80 (nonoverlapping) sites, each of approximately the same size. Due to time and cost constraints, the researchers would like to select five of these sites at random and send out one team of researchers to each site for observation. You are to select a simple random sample of size n=5 from a population of 80 sites. Use the random number table (Row 10, Column 1) to identify the 5 sites that would be selected from the 80 sites in the forest area. The row is reproduced below In this particular situation, the value of 12.5 A. parameter B. statistic 3. (1 pt) A particular gun-control bill is being sent to the U.S. Senate to be voted on. Each of the 50 states has two elected senators eligible to vote. To try to predict the outcome of the upcoming vote, a newspaper reporter randomly selected 10 Senators and asked each how he or she planned to vote. What is the population in this situation? A. randomly selected U.S. senators B. all U.S. senators The 5 sites selected are: A. 54, 75, 36, 57, 53 B. 47, 53, 68, 57, 53 C. 85, 47, 53, 68, 57 D. 47, 53, 68, 57, (1 pt) A student organization wants to assess the attitudes of students towards a proposed change in the hours that the undergraduate library is open. They randomly select 100 freshman, 100 sophomores, 100 juniors, and 100 seniors. What type of sampling design was used in this study? A. Stratified Random Sample

2 B. Simple Random Sample C. Systematic Random Sample D. Cluster Sample E. Multistage Sample 6. (1 pt) The College of Science at a certain university consists of five academic departments: (1) Physics, (2) Chemistry, (3) Biology, (4) Mathematics, (5) Geology. There are 50, 70, 20, 10, and 40 faculty members in the departments of Physics, Chemistry, Biology, Mathematics, and Geology, respectively. It was decided to select a cluster sample of two departments. Use the random number table (Row 15, Column 1). The row is reproduced below Using the above labels (1-5) and the random number table (Row 15, Column 1) which two departments are selected? A. Physics and Mathematics B. Biology and Geology C. Chemistry and Geology D. Physics and Biology What is the size of your cluster sample? 7. (1 pt) For each set of variables listed, identify which variable should be the response variable and which should be the explanatory variable 8. (1 pt) Read the following excerpts from the New York Times (December 17, 1996) article Chance of Heart Attack Increases for Those Who Suffer from Depression. A report in the December 16, 1996 issue of Circulation reports on a study that finds that those who are subjects to depression are four times more likely to have a heart attack than those who are not depressed. The study involved 1551 people in the Baltimore area who took part in a study in In this study, interviewers asked questions like In your lifetime, have you ever had two weeks or more in which you lost all interest and pleasure in things you usually cared about and enjoyed? They were also asked questions about unusual changes in their appetite and in their sleep. Based on this information, subjects were classified according to their depression status and their heart attack status was recorded. Of the 444 who were classified as having been depressed, 27, or 6.1 Is this study observational or experimental? A. experimental B. observational What is the response variable for this study? A. heart attack status B. depression status V1: The amount of money earned for a part-time job V2: The number of hours worked A. V1: explanatory variable, V2: response variable B. V1: response variable, V2: explanatory variable V1: The weight of a package V2: The first-class postage rate at the post office A. V1: response variable, V2: explanatory variable B. V1: explanatory variable, V2: response variable V1: The salary of a high school teacher V2: The number of years of teaching experience A. V1: response variable, V2: explanatory variable B. V1: explanatory variable, V2: response variable 2 What is the explanatory variable for this study? A. depression status B. heart attack status Is the value of 6.1 A. statistic B. parameter 9. (1 pt) The following data contains days when road rage occured according to a study. The goal of the study is to determine when road age occurs most often. Su, W, F, F, Th, F, Th, F, Th, F, M, F, F, W, Tu, F, F, F, Tu, F, F, Tu, Th, Tu, Sa, M, Tu, F, F, F, M, Sa, Su, W, W, M, Th, M, M, F, Su, W, Sa, F, Th, Su, F

3 Find the mode of the above data. 14. (1 pt) Calculate the mode, mean, and median of the following data: 10. (1 pt) Why is a sample often a better way to obtain information about a population than a census? A. A census is frequently impractical B. A census is too time consuming C. A census is more costly than taking a sample E. None of the above 11. (1 pt) (a) Count the number of ways to select a sample of 2 people to serve on a board of directors from a population of 6 people. answer: (b) If a simple random sampling procedure is to be employed, the chances that any particular sample will be the one selected are 12. (1 pt) Calculate the mode, mean, and median of the following data: Mean = Median = 19, 23, 16, 13, 19, 19, 22, 999 Which measure of center does not work well here? A. Mean B. Median C. Mode 13. (1 pt) To select 10 students out of the class of 40 students, I select every 4th name from the roster beginning with the 2nd student. What type of sample is this? A. Multistage Sample B. Stratified Random Sample C. Simple Random Sample D. Cluster Sample E. Systematic Random Sample Mean = Median = 5, 11, 17, 17, 8, 11, 11, (1 pt) A public opinion poll in Ohio wants to determine whether registered voters in the state approve of a measure to ban smoking in all public areas. They randomly select 50 voters from each county in the state and ask whether they approve or disapprove of the measure. A. SIMPLE RANDOM SAMPLE B. STRATIFIED RANDOM SAMPLE At a party there are 30 students over age 21 and 20 students under age 21. You randomly select 5 students to interview about attitudes toward alcohol. A. STRATIFIED RANDOM SAMPLE B. SIMPLE RANDOM SAMPLE The Ministry of Health in the Canadian Province of Ontario conducted the Ontario Health Survey by conducting interviews with 65,000 randomly selected residents of Ontario. A. SIMPLE RANDOM SAMPLE B. STRATIFIED RANDOM SAMPLE 16. (1 pt) For the equation y = 1 + 3x, a. the y-intercept is, and the slope is. b. the line A. slopes downward B. slopes upward C. is horizontal D. none of the above c. use two points to graph the equation. 3

4 17. (1 pt) The Boston Marathon is the world s oldest annual marathon, and is considered by many to be the pinnacle marathon event. Suppose you are given the results list for the men s open championships from 2003, providing finishing times for each competitor. What type of study is this? A. DESCRIPTIVE B. INFERENTIAL 18. (1 pt) Consider the following data set: Below is a partially completed stem-and-leaf diagram for this data set: 1 3 Determine the correct values for the missing entries, and fill them in. If no value is needed for a given entry, then enter X. 19. (1 pt) A summary measure that is computed from a population is called: A. a parameter B. a statistic C. a population D. both a parameter and a population since they are the same Descriptive statistics deals with methods of: A. presenting data in a convenient and informative way B. summarizing data C. organizing data (1 pt) Consider the following data set: Before leaving a particular restaurant, patrons are asked to respond to a questionaire containing the questions given below For each question, indicate (using the pull-down menu) whether the possible responses are Interval, Nominal, or Ordinal. Below is a partially completed stem-and-leaf diagram for this data set:? 1. Would you recommend this restaurant to a friend? Determine the correct values for the missing entries, and fill them in. If no value is needed for a given entry, then enter X. Determine whether the following possible responses should be classified as interval, nominal or ordinal data.? 1. Which of the following features of the hotel in New York did you find most attractive: location, facilities, room size, or price?? 2. Would your overall rating of this tour be excellent, good, fair, or poor?? 3. Do you feel that the stay in New York was sufficiently long?? 4. What is your political party affiliation? Determine whether the following possible responses should be classified as interval, nominal or ordinal data.? 1. The type of car you currently drive? 2. The college (Arts and Science, Business, etc.) you are enrolled in? 3. Your hometown? 4. The age of each of your classmates Select True or False from each pull-down menu, depending on whether the corresponding statement is true or false.? 1. Bar and pie charts are graphical techniques for nominal data. The former focus the attention on the frequency of the occurrences of the categories, and the later emphasize the proportion of occurrences in each category.? 2. If we draw a straight line through the points in a scatter diagram and most of the points fall close to the line, we say that there is a positive linear relationship between the two variables.? 3. Quantitative variables usually represent membership in groups or categories.? 4. An automobile insurance agent believes that company A is more reliable than company B. The scale of measurement that this information represents is the ordinal scale.? 2. Which of the following attributes of this restaurant do you find most attractive: service, prices, quality of food, menu options?? 3. What is the approximate distance of the restaurant from your home?? 4. Would your overall rating of this restaurant be excellent, good, fair, or poor?

5 Generated by the WeBWorK system c WeBWorK Team, Department of Mathematics, University of Rochester 5