Will Asemota AMS110-2 2 WeBWorK assignment number HW3 is due : 03/04/2014 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 27620.3413, etc. Here s the list of the functions which WeBWorK understands. You can use the Feedback button on each problem page to send e-mail 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?. Cluster Sample. Multistage Sample C. Stratified Random Sample. Systematic Random Sample E. Simple 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. parameter. statistic In this particular situation, the value of 12.5. statistic. parameter 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. 1 What is the population in this situation?. randomly selected U.S. senators. all U.S. senators What is the value of N, the population size? What is the sample in this situation?. all U.S. senators. randomly selected U.S. senators What is the value of n, the sample size? 100 10 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 85475 36857 53342 53988 53060 The 5 sites selected are:. 47, 53, 68, 57, 34
. 47, 53, 68, 57, 53 C. 54, 75, 36, 57, 53. 85, 47, 53, 68, 57 5. (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?. Stratified Random Sample. Multistage Sample C. Simple Random Sample. Systematic Random Sample E. Cluster 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 07119 97336 71048 08178 Using the above labels (1-5) and the random number table (Row 15, Column 1) which two departments are selected?. Chemistry and Geology. Biology and Geology C. Physics and Mathematics. Physics and Biology V1: The weight of a package V2: The first-class postage rate at the post office. V1: explanatory variable, V2: response variable. V1: response variable, V2: explanatory variable V1: The salary of a high school teacher V2: The number of years of teaching experience. V1: response variable, V2: explanatory variable. V1: explanatory variable, V2: response 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 1980. 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 What is the size of your cluster sample? 70 7. (1 pt) For each set of variables listed, identify which variable should be the response variable and which should be the explanatory variable V1: The amount of money earned for a part-time job V2: The number of hours worked. V1: response variable, V2: explanatory variable. V1: explanatory variable, V2: response variable 2 Is this study observational or experimental?. observational. experimental What is the response variable for this study?. depression status. heart attack status What is the explanatory variable for this study?. heart attack status. depression status
Is the value of 6.1. parameter. statistic 9. (1 pt) 12. (1 pt) Calculate the mode, mean, and median of the following data: 15, 24, 16, 16, 11, 999, 16, 19 Mean = Median = 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, Th, W, F, Sa, W, Th, M, Tu, Th, F, F, Tu, Sa, M, Sa, Th, W, M, F, F, F, W, Su, Th, M, M, Tu, F, M, Su, Tu, F, F, F, F, Su, Th, F, F, Th, W, Sa, M, Tu, F Find the mode of the above data. F 10. (1 pt) Why is a sample often a better way to obtain information about a population than a census?. A census is too time consuming. A census is more costly than taking a sample C. A census is frequently impractical. All of the above 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 5 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 10 0.1 Which measure of center does not work well here?. Mean. Median C. Mode. All of the above 139.5 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?. Systematic Random Sample. Simple Random Sample C. Cluster Sample. Stratified Random Sample E. Multistage Sample 14. (1 pt) Calculate the mode, mean, and median of the following data: Mean = Median = 16, 6, 12, 14, 16, 21, 16, 18 3
14.875 15. (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 in the state and ask whether they approve or disapprove of the measure.. SIMPLE RANDOM SAMPLE. 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.. STRATIFIED RANDOM SAMPLE. SIMPLE RANDOM SAMPLE The Ministry of Health in the Canadian Province of Ontario conducted the Ontario Health Survey by conducting interviews with 30,000 randomly selected men and 35,000 randomly selected women who reside in Ontario.. SIMPLE RANDOM SAMPLE. STRATIFIED RANDOM SAMPLE 16. (1 pt) For the equation y = 8 + 5x, a. the y-intercept is, and the slope is. b. the line. is horizontal. slopes upward C. slopes downward. none of the above c. use two points to graph the equation. 8 5 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 finishing times of a sample of 15 marathon runners for the men s open championships from 2003. What type of study is this?. DESCRIPTIVE. INFERENTIAL 18. (1 pt) Consider the following data set: 33 48 15 33 39 12 23 54 23 44 12 24 53 13 54 39 23 20 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. 2235 2 03334 3399 4 5 344 48 19. (1 pt) Descriptive statistics deals with methods of:. summarizing data. presenting data in a convenient and informative way C. organizing data. All of the above A summary measure that is computed from a population is called:. a population. a parameter C. a statistic. both a parameter and a population since they are the same 4
20. (1 pt) Consider the following data set: 177 183 176 165 168 185 165 163 181 163 167 168 167 183 183 176 187 165 177 161 184 176 Below is a partially completed stem-and-leaf diagram for this data set: 16 16 17 Determine the correct values for the missing entries, and fill them in. If no value is needed for a given entry, then enter X. 133 5557788 17 X 66677 18 13334 18 57 Determine whether the following possible responses should be classified as interval, nominal or ordinal data.? 1. Do you feel that the stay in New York was sufficiently long?? 2. Would your overall rating of this tour be excellent, good, fair, or poor?? 3. What is the current temperature outside?? 4. What is your political party affiliation? Ordinal Determine whether the following possible responses should be classified as interval, nominal or ordinal data.? 1. The college (Arts and Science, Business, etc.) you are enrolled in? 2. The letter grades received by students in a computer science class? 3. The number of students in a statistics course? 4. The starting salaries of new Ph.D. graduates from a statistics program Ordinal Select True or False from each pull-down menu, depending on whether the corresponding statement is true or false.? 1. The graphical technique used to describe the relationship between two interval variables is the scatter diagram.? 2. 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.? 3. 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.? 4. 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. F 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.? 1. Which of the following attributes of this restaurant do you find most attractive: service, prices, quality of food, menu options?? 2. If you ve eaten here before, how long has it been since your last visit?? 3. Do you consider our prices to be high, average, or low?? 4. Would your overall rating of this restaurant be excellent, good, fair, or poor? N I O O Generated by the WeBWorK system c WeBWorK Team, Department of Mathematics, University of Rochester 5