STA 210 Rayens Exam 1 content

Quiz 5: A population has 50 items, 21 green and 29 red. Turns out there are 2118760 possible samples of size 5 that can be taken from this population. Supposed you computed the sample proportion of green in each of these 2118760 samples of size 5 and added them all up. What would you get? a. 21/50 b. 889879.2 c. 29/50 d. 1228880.8

b. 889879.2

Quiz 5: What is "response substitution?" a. This is the tendency for survey respondents to present their answers in a way that allows them to express their opinions about other issues that aren't the topic of the survey b. This is the desire of the interviewee to be looked at favorably by the interviewer and, as such, will purposely conform to social norms. c. This is the threat of being stereotyped or confirming a negative stereotype. d. This is the tendency for survey respondents to substitute questions for those that are worded poorly or are hard to understand.

a. This is the tendency for survey respondents to present their answers in a way that allows them to express their opinions about other issues that aren't the topic of the survey

2.8: You have enough money to interview 90 residents. Working much the way Gallup did in the 1930s you want your sample of 90 to mirror the distribution of subjects in the population exactly (at least along the lines of gender, income,and political affiliation). How many people would your sample place in the group "Males making between $40,000 and $80,000 yearly?" If your calculation results in a partial person, leave the number as it is-don't round. a. 20 b. 1.5 c. 40 d. 6.4

a. 20

Quiz 3: Suppose you have a data set with 1000 observations in it. 500 of those are all 5 and 500 are 15. Then the standard deviation is about? a. About 5 b. 2.51 c. Can't tell from information given d. About 25

a. About 5

Quiz 9: Refer to the graphic below. We encountered this summary of the sampling distribution of the sample proportion in class. Suppose n = 100. What are the chances of an SRS of this size yielding a phat that is somewhere between p - 0.1 and p + 0.1? a. 13.5 out of 100 b. 95 out of 100 c. 99.7 out of 100 d. 68 out of 100

b. 95 out of 100

Quiz 9: Refer to the graphic below. We encountered this summary of the sampling distribution of the sample proportion in class. Specify an interval (range) in which 68% of all sample proportions based on samples of size n could be expected to occur. a. Within (0.5)x(1/sqrt(n)) on either side of the parameter p. b. Within (0.5)x(1/sqrt(n)) on either side of the sample proportion phat. c. Within (1/sqrt(n)) on either side of the sample proportion phat. d. Within (1/sqrt(n)) on either side of the parameter p.

a. Within (0.5)x(1/sqrt(n)) on either side of the parameter p.

1.10: Exhibit 3, Question 3 - A snoozing journalist woke up just after Mr. Gates got on. She proceeded to do a survey of salaries for the nine riders and reported the average the next day in the paper. Would this allow for an inaccurate inference regarding the typical income of Seattle residents? a. Yes, it would be much too high. b. No, it would be about right. Everyone understands that the typical Seattle resident is not Mr. Gates. c. Yes, it would be way too low. d. No it would be about right. The mean is not sensitive to large outlier numbers like Mr. Gates' salary.

a. Yes, it would be much too high.

2.9: Professors Gal and Rucker used a plot very much like the one shown on page 152 to argue that these results are "consistent with response substitution because wastefulness led to more negative perceptions of intelligence when participants did not have an opportunity to provide their attitude toward wastefulness." How does the plot support that conclusion? a. Anne was perceived as wasteful. So if her intelligence was rated before her wastefulness, then she got lower intelligence scores. b. Jane was perceived as wasteful. So if her intelligence was rated before her wastefulness, then she got lower intelligence scores. c. Anne was perceived as wasteful. So if her intelligence was rated before her wastefulness, then she got higher intelligence scores. d. Jane was perceived as wasteful. So if her intelligence was rated before her wastefulness, then she got lower wastefulness scores.

a. Anne was perceived as wasteful. So if her intelligence was rated before her wastefulness, then she got lower intelligence scores

2.6: Refer to Exhibit 3, Question 1. What is the population being referred to? a. The 113 Facebook Friends mentioned b. All people who are Friends on some Facebook account c. The 20 Facebook Friends chosen

a. The 113 Facebook Friends mentioned

Quiz 3: Suppose you have a data set with 1000 observations in it. 500 of those are all 5 and 500 are 15. What of the following are true? a. The mean and median are the same b. The mean is bigger than the median c. The mean is smaller than the median d. The mean is 0

a. The mean and median are the same

Quiz 1: Which of the following statements do you think could possibly be true? a. The number of students enrolled at Midville University decreased by 10.4% last year. b. A basketball team took 20 free throws in a game last week and made 72.6% of them. c. Yesterday it was 30° (Fahrenheit) in Chicago. Today it warmed up to 60°. This is a 50% increase in the temperature. d. My weight decreased by 10% last year but then increased by 10% in the first two months of this year. Thus, my overall weight from the beginning of last year until now is unchanged.

a. The number of students enrolled at Midville University decreased by 10.4% last year.

Quiz 4: What are the two keys to having confidence in your parameter estimate? a. The probabilistic nature of the sample selection, and some neat mathematics that follow from this. b. Knowing that you did a good job, and understanding the population context. c. Always being upbeat when interviewing subjects and avoiding confounding variables. d. Making sure your sample is representative of your population, and making sure you are able to do the subsequent computations with integrity.

a. The probabilistic nature of the sample selection, and some neat mathematics that follow from this.

Quiz 3: Which of the following statements is true? a. The mean is sensitive to outliers but the standard deviation is not b. The median is sensitive to outliers but the mean is not c. The mean and standard deviation are sensitive to outliers d. The mean and median are sensitive to outliers

c. The mean and standard deviation are sensitive to outliers

1.11: Exhibit 1, Question 1 - Use a software package such as Microsoft Excel or Apple Numbers to compute the mean and the median of the entire 18-person data set ("Data Set 1"). What is the median? a. 72 b. 89.3 c. 86.1 d. 80.5

d. 80.5

1.12: Compute and interpret the ratio: s = (standard deviation of Data Set 1)/(standard deviation of Data Set 2) a. The ratio is 3.09 which means that Data Set I is about 3 times more spread out than Data Set II. b. The ratio is 9.03 which means that Data Set I is about 9 times more spread out than Data Set II. c. The ratio is 3.09 which means that Data Set Ii is about 3 times more spread out than Data Set I. d. The ratio is 9.03 which means that Data Set II is about 9 times more spread out than Data Set I.

a. The ratio is 3.09 which means that Data Set I is about 3 times more spread out than Data Set II.

2.22: Exhibit 2, Question 2 (second part): What was the actual percentage of answers in this interval? a. 18% b. 68% c. 99% d. 9.9%

d. 9.9%

Quiz 6: What can one say about the sampling distribution of a sample statistic based on a simple random sample? a. it is about bell-shaped and peaks above the parameter b. it is usually skewed if the population concerns incomes c. it will be roughly a straight line. d. nothing can be said in advance about the sampling distribution since the sampling was random

a. it is about bell-shaped and peaks above the parameter

1.10: Exhibit 3, Question 1 - What is the new average salary of people on the bus? a. $844,496,111. b. $585,000. c. $120,000. d. $465,000,000.

a. $844,496,111.

2.6: Exhibit 2, Question 2 noted that for a simple random sample of size 2, all samples of size 2 have the same chance of being chosen. What would the likelihood be of choosing any one of these samples (expressed as a decimal) if there were 100 different samples of size 2? a. 0.01 b. 0.1 c. 0.0001 d. 100.00

a. 0.01

2.10: Question 4, Exhibit 1: Suppose the following data had been selected: What is the average BAC? a. 0.1447 b. 0.5491 c. 0.3215 d. 0.0118

a. 0.1447

2.12: Question 3, Exhibit 2: Suppose that in the larger population, half of all likely voters are Democrats and half are Republicans. Now imagine that our simple random sample was comprised of 50 Democrats and 50 Republicans (instead of 80 Democrats and 20 Republicans). Re-compute the proportion of likely voters who planned to vote for Barack Obama. What is the result of that computation? a. 0.45 b. 0.54 c. 0.35 d. 0.04

a. 0.45

2.12: Question 1, Exhibit 2: What proportion of likely voters overall (Democrats and Republicans combined) planned to vote for Barack Obama? a. 0.60 b. 0.54 c. 0.04 d. 0.45

a. 0.60

2.10: Question 5, Exhibit 1: Suppose the following data had been selected: What proportion of cases in the sample shown in the table above had BACs at or above the legal limit of 0.04? a. 0.95 b. 0.l9 c. 0.01 d. 0.38

a. 0.95

1.12: Exhibit 1, Question 1 - The wingspan of nine ordinary persons and nine current or former NBA players are shown in the table. Use a software package such as Microsoft Excel or Apple Numbers to compute the variance and standard deviation of these 18 wingspans (Data Set 1). What is the standard deviation? a. 11.8 b. 400.5 c. 140.3 d. 20.1

a. 11.8

Quiz 7: If you want a 95% margin of error to be 1%, what will your sample size have to be? a. n = 10000 b. n = 100 c. n = 10 d. n = 1000000

a. n = 10000

1.9: Exhibit 2, Question 2 - Initially, the government was reluctant to collect more than the most basic census information of race, sex, and age. Why? a. As one representative said, it would "occasion an alarm" among the people, for "they would suppose the government intended something, by putting the union to this additional expense, besides gratifying an idle curiosity." b. As one representative said, it would "occasion an alarm" among the people, for "they would suppose the government would eventually require all to be trained in the art of statistical reasoning." c. As one representative said, it would "occasion an alarm" among the people, for "they would suppose the government was trying to create a data base from which to spy on residents." d. As one representative said, it would "occasion an alarm" among the people, for "they would suppose the government was trying to create a data base from which create an unfair apportionment of collected taxes."

a. As one representative said, it would "occasion an alarm" among the people, for "they would suppose the government intended something, by putting the union to this additional expense, besides gratifying an idle curiosity."

Quiz 5: Consider the following survey question: "The Mac operating system rarely gets infected by viruses and therefore Department of Education should only purchase Mac computers. Please answer Yes or No". What is one objection to this question, as asked? a. Because of the "rarely gets infected by viruses" clause this question is a leading question. b. It won't necessarily be clear what one means by a Mac operating system." c. Only have two possible answers severely limits the breadth of expression for the respondent. d. It would be silly to ask this question to people who don't have any purchasing power in the College of Education

a. Because of the "rarely gets infected by viruses" clause this question is a leading question.

2.12: Question 1, Exhibit 1. What is the actual population being addressed by a Gallup telephone survey? Be very precise with your answer? a. Gallup refers to the target audience as "national adults," representing all adults, aged 18 and older, living in United States b. Gallup refers to the target audience as all Americans, regardless of age, living in United States c. Gallup refers to the target audience as all adults, with cell phones of course, living in the central 48 states.

a. Gallup refers to the target audience as "national adults," representing all adults, aged 18 and older, living in United States

Quiz 10: Recall Harris Poll disclaimer mentioned in the Read All About It (or the video). Harris is a major polling organization that refuses to accompany their poll reports with a margin of error. What is one reason that was given for such a bold omission? a. Harris recognizes that there are many sources of error that are not addressed by the MOE, so reporting it might be misleading. b. Harris recognizes that the MOE is simply too difficult to calculate, so why bother. c. Harris claims that poll participation rates are so high that the MOE doesn't add anything useful. d. Harris claims that publication sponsors simply don't want to see the MOE reported any longer.

a. Harris recognizes that there are many sources of error that are not addressed by the MOE, so reporting it might be misleading.

Quiz 10: In the MOE Doesn't Apply Read All About It (or video), what was the issue with the question "Have you often, sometimes, hardly ever, or never felt bad because you were unfaithful to your wife?" a. Of the 85% who said they "never felt bad about it" surely a large part of those had never been unfaithful to their wives. But the way the question was asked this wasn't an option for an answer. b. Of the 15% who said they "never felt bad about it" surely a large part of those had never been unfaithful to their wives. But the way the question was asked this wasn't an option for an answer. c. Of the 15% who said they "never felt bad about it" surely most of them had really been unfaithful to their wives. But the way the question was asked there wasn't an option for them to say how. d. Of the 85% who said they "never felt bad about it" surely most of them had really been unfaithful to their wives. But the way the question was asked there wasn't an option for them to say how.

a. Of the 85% who said they "never felt bad about it" surely a large part of those had never been unfaithful to their wives. But the way the question was asked this wasn't an option for an answer.

Quiz 1: What do we mean by "human inference?" a. Off-hand phrase taken to mean inference we make from statistical constructs b. Off-hand phrase taken to mean "statistically significant." c. Off-hand phrase taken to mean that humans, not lab animals, were the experimental subjects. d. Off-hand phrase taken to mean basic numeracy.

a. Off-hand phrase taken to mean inference we make from statistical constructs

Quiz 1: The claim has been made that over 4 million women in the U.S. are battered to death each year by a spouse or boyfriend. What is wrong with this claim? a. Only about 2.4 million people die in the U.S. each year from all causes. b. Only about 300,000 people die in the U.S. each year from all causes. c. Only about 2.4 thousand people die in the U.S. each year from all causes. d. Only about 4 million people die in the U.S. each year from all causes.

a. Only about 2.4 million people die in the U.S. each year from all causes.

1.10: Exhibit 3, Question 2 - What can you say about the new median salary of people on the bus? a. Same as it was before. b. Smaller than it was before. c. Larger than it was before. d. It is impossible to know from the information given.

a. Same as it was before.

2.9: According to the authors of this study, what is one way to address response substitution? a. Tell the consumers that, after the survey is over, they'll have the opportunity to express any opinion they might have. b. Tell the consumers that it is a violation of survey research ethics to pre-judge a person in the absence of any hard facts. c. Tell the consumers to make sure they only answer the questions being asked and that they don't allow their thoughts to wander to things they'd really like to say.

a. Tell the consumers that, after the survey is over, they'll have the opportunity to express any opinion they might have.

Quiz 9: In BN 2.20 we found that out of 594 people asked (students, researchers), 281 reported that the right way to interpret a 95% confidence interval of 0.1 to 0.4 was to say that "the probability that the true proportion is bigger than 0 is at least 95%." What is wrong with that interpretation? a. That makes it sound like the parameter is random. It is not. b. That makes it sound like the confidence interval is random. It is not. c. That makes it sound like that 0 is in the interval 0.1 to 0.4. It is not. d. That makes it sound like the sample proportion is random. It is not.

a. That makes it sound like the parameter is random. It is not.

Quiz 6: You ask a question to a random sample of 1000 adults in Texas (population 18 million people) and to a separate random sample of 1000 adults in Indiana (population 5.7 million people). You make separate 95% confidence statements about the percent of all adults in each state who agree. Your margin of error for Indiana is a. the same as in Texas, because the two samples are the same size. b. larger than in Texas, because there are fewer people in Indiana. c. smaller than in Texas, because there are fewer people in Indiana. d. may be either smaller or larger than in Texas, because the sample result varies due to chance.

a. the same as in Texas, because the two samples are the same size.

1.11: Exhibit 3, Question 3 - Let's play a game. It costs you $25.00 to play. Here are the rules. You get to pick two wingspans at random, eyes closed, out of either Data Set 1 or Data Set 2 (not both). Your choice. Call your choices x1 and x2. You will receive a reward of $(80.5 − x1)2 + $(80.5 − x2)2. If you pick from Data Set 2, what is the maximum profit you can make? a. $50 b. $25 c. $75 d. $100

b. $25

1.9: Exhibit 1, Question 1 - If 1 milliliter equals 100 insulin units, how many milliliters should the patient have been given if she had been prescribed 36 units? a. 1 milliliter = 100 units so 0.1 milliliter = 1 unit. It follows that 3.6 milliliters = 36 units. So she should have injected the patient with 3.6 milliliters. b. 1 milliliter = 100 units so 0.01 milliliter = 1 unit. It follows that 0.36 milliliters = 36 units. So she should have injected the patient with 0.36 milliliters. c. 1 milliliter = 10 units so 0.1 milliliter = 1 unit. It follows that 3.6 milliliters = 36 units. So she should have injected the patient with 3.6 milliliters. d. 1 milliliter = 100 units so 0.01 milliliter = 10 units. It follows that 3600 milliliters = 36 units. So she should have injected the patient with 3600 milliliters.

b. 1 milliliter = 100 units so 0.01 milliliter = 1 unit. It follows that 0.36 milliliters = 36 units. So she should have injected the patient with 0.36 milliliters.

Quiz 1: In the New York Times Magazine, Tara Parker-Pope makes the case that teenagers are more conservative than their parents were. For example, the fraction of high-school seniors who reported that they had recently consumed alcohol fell from 72% in 1980 (illustrated as the big one-gallon - 128 ounce - jug) to 40% in 2011 (illustrated as the little 8-ounce glass). The actual percent "Parents" consumption divided by percent "Kids" consumption is approximately _____ but the graphic makes that ratio look more like _____. The two best answers for filling in these blanks (in respective order) are: a. 1.8 and 1.6 b. 1.8 and 16 c. 32 and 120 d. 32 and 1.6.

b. 1.8 and 16

Quiz 2: Are you numerate? Here's a question from the workbook that will help you decide. An article entitled "Cocaine Floods the Playground: Use of the Addictive Drug by Children Doubles in a Year" appeared in 2006 in The Times. Here is an excerpt of what the authors said "Cocaine use among children has doubled in a year as the fashionable drug of the middle classes extends its reach from the dinner party to the playground. Hundreds of thousands of 11 to 15-year-olds are being offered the Class A drug .... Figures published yesterday showed that cocaine use among 11 to 15-year-olds doubled from 1 percent to 2 percent between 2004 and 2005." Here is the table the authors refer to: Where did the justification for use of the word doubled likely come from? a. 1.9/1.4 is about 1.8 which rounds to 2 b. 1.9 is about 2 and 1.4 is about 1 so that is likely the source for the word "doubles." c. 1.4 truncates to .4 and 1.9 truncates to .9 and .9 is just a little more than double .4 d. 1.9 in 2005 rounds to 2, so produces the justification for saying "doubles."

b. 1.9 is about 2 and 1.4 is about 1 so that is likely the source for the word "doubles."

2.22: Question 2, Exhibit 1: Suppose a college student is selected at random. Use the empirical rule to estimate how likely it is that this student studies between 17.5 and 20 hours per week. a. 27 chances in 100 b. 13.5 chances in 100 c. 86.5 chances in 100 d. 95 chances in 100

b. 13.5 chances in 100

Quiz 2: In the piece on Deathly Hallow's book sales, it was claimed that more than 50,000 were sold per minute on the average. What was wrong with this figure? a. 300,000 were sold on average each hour. That means only 500 were sold per minute. Decimal error. b. 300,000 were sold on average each hour. That means only 5000 were sold per minute. Decimal error. c. 300,000 were sold on average each hour. 300,000/60 = 50,000 so nothing is wrong with the number reported in the piece. The reviewer of the article who brought this up was just mistaken. d. 600,000 were sold on average per hour. That means that 10,000 were sold per minute, not 50,000. Arithmetic mistake.

b. 300,000 were sold on average each hour. That means only 5000 were sold per minute. Decimal error.

2.20: About how many study subjects agreed with Statement 3? a. 600 b. 343 c. 123 d. None agreed

b. 343

Quiz 8: A recent poll of 1500 college-age students found that 885 agreed with U.S. foreign policy toward Israel. What is the corresponding 95% confidence interval (choose closest answer)? a. 59% plus or minus 95% b. 59% plus or minus 3% c. 885 plus or minus 95 d. 885 plus or minus 3%

b. 59% plus or minus 3%

2.8: You have enough money to interview 90 residents. Working much the way Gallup did in the 1930s you want your sample of 90 to mirror the distribution of subjects in the population exactly (at least along the lines of gender, income,and political affiliation). How many people would your sample place in the group "Male Republicans making over $80,000 per year?" If your calculation results in a partial person, leave the number as it is-don't round. a. 1.5 b. 6.4 c. 40 d. 20

b. 6.4

2.22: Question 1, Exhibit 2 (first part): Use the empirical rule to estimate how likely it is that an answer to this question will be in the interval 2.10 to 4.20 a. 32 chances in 100 b. 68 chances in 100 c. 50 chances in 100 d. 13.5 chances in 100

b. 68 chances in 100

Quiz 6: In a 2012 Gallup poll, eighty-two percent of adult U.S. Catholics say birth control is morally acceptable. Results for this poll are based on telephone interviews conducted May 3-6, 2012, with a random sample of 1,024 adult Catholics, aged 18 and older, living in all 50 U.S. states and the District of Columbia. What is the corresponding 95% confidence interval for the proportion of all adult U.S. Catholics who feel birth control is morally acceptable? a. 0.82 plus or minus 3% b. 82% plus or minus 3% c. 0.82 plus or minus 0.001 d. There are two correct answers listed here.

b. 82% plus or minus 3%

Quiz 4: What is a simple random sample? a. A sample chosen in such a way that you can be sure that subject characteristics (e.g. "male" and "female") will perfectly reflect the population. b. A sample chosen in such a way that all samples of that same size have the same chance of being chosen. c. A sample chosen in such a way that all samples of that same size have some chance of being chosen. d. A sample chosen in such a way that any given individual in the population has a 50-50 chance of being included (that is, either she is included or she is not).

b. A sample chosen in such a way that all samples of that same size have the same chance of being chosen.

2.20: You are given five statements in Table 2.7. Which of those are correct statements? a. Only Statement 4 b. All of the statements are wrong. c. Only Statement 5 d. Statements 4 and 5

b. All of the statements are wrong.

Quiz 10: What is a non-sampling error? a. Error due to non-sampling random fluctuation b. An error caused by something other than the fact that a sample was selected instead of the entire population. c. An error caused by the fact that something other than a sample was taken d. Error due to sampling variability

b. An error caused by something other than the fact that a sample was selected instead of the entire population.

Quiz 2: Refer to Question 1. What is the likely "human inference" and what is the "statistical construct" that is being used to produce it? a. Human inference is that cocaine use is out of control and the statistical construct is the 1.4. b. Human inference is that cocaine use is out of control and the statistical construct is the ratio 2-to-1. c. Human inference is that the ratio is for all practical purposes 2-to-1 and statistical construct is the evidence that cocaine use is out of control. d. Human inference is that the ratio is in reality 1.9 to 1.4 and the statistical construct is that cocaine use is not as bad as the headline says.

b. Human inference is that cocaine use is out of control and the statistical construct is the ratio 2-to-1.

2.6: Refer to Question 3, Exhibit 2. Suppose for a sample of size two to be "representative" of the population, it has to have exactly one man and one woman, and one Democrat and one Republican. What is the chance of selecting a simple random sample of size two from this population that is representative (in this sense of the word)? Assume your samples are (MR, MD), (MR, FR), (MR, FD), (MD,FR), (MD, FD), (FR,FD), where M stands for male, F for female, R for Republican and D for Democrat. a. Any of the six will work b. Only (MR,FD), (MD,FR) will work. c. Only (MR,MD) and (MR, FD) will work d. None of the samples of size 2 are representative

b. Only (MR,FD), (MD,FR) will work.

Quiz 10: What kind of error does the margin of error address? a. Fabrication errors b. Random sampling error c. Non-mathematical error d. Non-sampling error

b. Random sampling error

1.9: Exhibit 1, Question 2 - The nurse injected the patient four times with a full 0.9 milliliter syringe. What was the nurse's mistake? a. She got her decimal points wrong. She injected with 3.6 milliliters instead of 0.36 milliliters, a full 100 times as much as she should have. b. She got her decimal points wrong. She injected with 3.6 milliliters instead of 0.36 milliliters, a full ten times as much as she should have. c. She got her decimal points wrong. She injected with 36 milliliters instead of 3.6 milliliters, a full 100 times as much as she should have. d. She got her decimal points wrong. She injected with 36 milliliters instead of 3.6 milliliters, a full 10 times as much as she should have.

b. She got her decimal points wrong. She injected with 3.6 milliliters instead of 0.36 milliliters, a full ten times as much as she should have.

2.8: Suppose the cross-sectional sample taken above represents a perfect microcosm of the larger population with respect to the legalization of marijuana. Is there any uncertainty involved in using this sample to represent the proportion of people in Gulliver who favor the legalization of marijuana? Say why or why not. a. There would still be uncertainty about what the population felt at that very moment in time. Even if you had a perfect microcosm. Nothing is for certain. b. There would be no uncertainty about what the population felt at that very moment in time. Not if you had a perfect microcosm. c. There would be still be uncertainty about what the population felt at that very moment in time. Even a perfect microcosm is still just a sample. d. There would be no uncertainty about what the population felt at that very moment in time. The same would be true even if you didn't have a perfect microcosm, just as long as you had a good sample..

b. There would be no uncertainty about what the population felt at that very moment in time. Not if you had a perfect microcosm.

1.11: Exhibit 3, Question 1 - Compare the data sets from Exhibit 1 and Exhibit 2. How close are their average values? a. Average in Exhibit 2 is larger. b. They are identical c. Average in Exhibit 1 is larger. d. Can't tell from the information given in the prompt!

b. They are identical

Quiz 1: The well-respected journal Science, in an article on insects and plants, mentioned a California field that produced 750,000 melons per acre. How do you react to that? It may help you know that an acre is 43,560 square feet. a. This is reasonable, suggesting about 1.7 melons per square foot b. This is unreasonable, suggesting about 17 melons per square foot c. This is reasonable, suggesting about 5.8 melons per square foot d. This is unreasonable, suggesting about only 0.05 melons per square foot

b. This is unreasonable, suggesting about 17 melons per square foot

Quiz 4: What is the goal of sampling? a. To make inferences about a sample from what we know about our population. b. To make inferences about a population from what we know about our sample. c. To make inferences about a statistic that is unknown. d. To make inferences about a topic that is not numerical, and hence not calculable.

b. To make inferences about a population from what we know about our sample.

2.10: Question 2, Exhibit 1: When you take this problem to Research Randomizer, what would be the values for: a) How many sets of numbers do you want to generate? b) How many numbers per set? c) Number range (e.g. 1-50)? a. a) 1; b) 20; c) 1 to 73. b. a) 1; b) 20; c) 1 to 296. c. a) 296; b) 1; c) 1 to 20. d. a) 20; b) 1; c) 1 to 296.

b. a) 1; b) 20; c) 1 to 296.

Quiz 10: Which of the following are examples of strategies for reducing non-sampling errors? a. Use of inducements for non-responders b. Awareness of psychology of question order c. Use of technology-assisted confidential interview techniques d. All of those listed here

d. All of those listed here

Quiz 8: The distribution shown here represents the sampling distribution that resulted from 44 simple random samples, each of size 50, taken from a manufactured population of 250 voters. In each case the proportion of sampled voters who agreed President Trump was doing a good job was recorded. From what you know about sampling distributions arising from simple random samples, which of the following is the most likely value of the true proportion of all 250 voters who would have agreed, had they all been asked? a. 0.32 b. 0.19 c. 0.27 d. Can't tell from the figure given.

c. 0.27

1.12: Exhibit 1, Question 2 - Suppose that Data Set 2 consisted of 18 persons—eight with a wingspan of 80.5 inches, five with a wingspan of 75.5, and five with a wingspan of 85.5. Find the variance and standard deviation of these 18 wingspans. What is the variance? a. 3.8 b. 6.2 c. 14.7 d. 37.6

c. 14.7

2.22: Question 3, Exhibit 1: Suppose a college student is selected at random. Use the empirical rule to estimate how likely it is that this student studies more than 20 hours per week. a. 95 chances in 100 b. 2.35 chances in 100 c. 2.5 chances in 100 d. 5 chances in 100

c. 2.5 chances in 100

2.9: What was the Treatment 3 average? a. 2.67 b. 2.16 c. 3.06 d. 3.02

c. 3.06

Quiz 7: How much does the typical homework assignment (a single BN) count in this class? a. 4 points b. 3 points c. 5 points d. 2 points

c. 5 points

Quiz 9: The scores for all high school seniors taking the verbal section of the Scholastic Aptitude Test (SAT) in a particular year had a mean of 490 and a standard deviation of 100. The distribution of SAT scores is bell-shaped. A rather exclusive university only admits students who were among the highest 16% of the scores on this test. What minimum score would a student need on this test to be qualified for admittance to this university? a. 490 b. 690 c. 590 d. 390

c. 590

2.22: Question 1, Exhibit 2 (second part): What was the actual percentage of answers in this interval? a. 52% b. 181% c. 61.33% d. 59%

c. 61.33%

1.11: Exhibit 1, Question 1 - Use a software package such as Microsoft Excel or Apple Numbers to compute the mean and the median of the entire 18-person data set ("Data Set 1"). What is the mean? a. 72 b. 86.1 c. 80.5 d. 89.3

c. 80.5

Quiz 4: What is a cross-sectional sample? a. An attempt to match the sample characteristics exactly to the type of people you prefer to interview. b. An attempt to match the population characteristics exactly to those of an already-taken sample. c. An attempt to match the sample characteristics exactly to those of the population. d. An attempt to match up pairs of people in the sample so that they look exactly like corresponding pairs in the population.

c. An attempt to match the sample characteristics exactly to those of the population.

Quiz 7: What happens to the margin of error as the sample size gets larger? a. It will depend on the sample b. It stays the same c. It decreases d. It increases

c. It decreases

Quiz 6: A 1996 Gallup poll of eligible New Hampshire primary voters reported that "of 1200 voters surveyed, 24% would vote for Senator Bob Dole if the primary election were held today". The Gallup organization also reported that the margin of error for a sample of 1200 people is 3 percentage points. If the Gallup organization had wanted to make a confidence statement based on the same data, only with more confidence that the interval had captured the parameter, what do you think would happen to the margin of error? It would be a. Smaller than 3%. b. Still 3%. c. Larger than 3%. d. Essentially infinite, because less confidence is not possible with this small a sample.

c. Larger than 3%.

2.22: Question 1, Exhibit 1: Suppose a college student is selected at random. Use the empirical rule to estimate how likely it is that this student studies between 10 and 17.5 hours per week? a. Mean is 15 and standard deviation is 5. So 10 is one standard deviations below and 20, which is only a bit larger than 17.5, is one standard deviation above. From the graph then this probability is 34 + 34 = 68 chances in 100. b. Mean is 15 and standard deviation is 2.5. So 10 is two standard deviations below and 17.5 is one standard deviation above. From the graph then this probability is 100-(13.5 + 34 + 34) = 100- 81.5 = 18.5 chances in 100. c. Mean is 15 and standard deviation is 2.5. So 10 is two standard deviations below and 17.5 is one standard deviation above. From the graph then this probability is 13.5 + 34 + 34 = 81.5 chances in 100. d. Either the student does (probability of .5) or doesn't (probability of .5) study between 10 and 17.5 hours per week. So the chances are 1 in 2.

c. Mean is 15 and standard deviation is 2.5. So 10 is two standard deviations below and 17.5 is one standard deviation above. From the graph then this probability is 13.5 + 34 + 34 = 81.5 chances in 100.

Quiz 4: What does the word "parameter" refer to in statistical science? a. Number that describes the sample b. The size of the sample c. Number that describes the population d. The set of guidelines for the selecting the sample

c. Number that describes the population

2.12: Question 2, Exhibit 2: Do you think the proportion you provided above is an underestimate or an overestimate? Why? a. Probably an overestimate since four times as many Republicans were in the sample as Democrats. b. Probably an underestimate since four times as many Democrats were in the sample as Republicans. c. Probably an overestimate since four times as many Democrats were in the sample as Republicans. d. Probably neither an overestimate nor an underestimate since the initial sample was a simple random sample (or equivalent to one).

c. Probably an overestimate since four times as many Democrats were in the sample as Republicans.

Quiz 5: A student in a statistics class is about to start a survey sampling project. She has 113 Facebook friends and wants to distribute a questionnaire to 20 of them. Which of the following sampling plans would be the most like a real-world simple random sample? a. Post the questionnaire on Facebook and take the 20 responses you get. No reason to believe the first 20 are not just random from the larger group. b. Post the questionnaire on Facebook and wait until you get as many of the 113 responses as you can. Then select 20 of those at random. c. Select 20 names at random from the 113 Friends and contact those 20 with the questionnaire. d. Select several different samples of size 20 names from the 113 Friends. Contact each group of 20 with the questionnaire and then average the responses you get from each of those groups.

c. Select 20 names at random from the 113 Friends and contact those 20 with the questionnaire.

2.12: Question 2, Exhibit 1: In what sense can a directory-assisted random-digit-dial sample be thought of as a simple random sample? a. The numbers selected are chosen at random (by a computer) from all working exchanges. So in that sense any given set of working numbers should not have the same chance of being chosen as any other set of working numbers of the same size. This uniqueness is required for a (simple) random sample. b. The numbers selected are chosen at random (by a computer) from all working exchanges. So in that sense any set of working numbers chosen should be effectively representative of all working numbers available. c. The numbers selected are chosen at random (by a computer) from all working exchanges. So in that sense any set of working numbers should have the same chance of being chosen as any other set of working numbers of the same size. d. The numbers selected are chosen at random (by a computer) from all working exchanges. So in that sense any set of working numbers chosen should be demographically balanced.

c. The numbers selected are chosen at random (by a computer) from all working exchanges. So in that sense any set of working numbers should have the same chance of being chosen as any other set of working numbers of the same size.

Quiz 6: What is sampling variability? a. The variability seen in parameters from sample to sample. b. The variability seen in statistics over time c. The variability seen in statistics from sample to sample d. The variability seen in parameters over time.

c. The variability seen in statistics from sample to sample

2.8: A carefully chosen simple random sample may not be representative of the population. How this could be? a. There is always some chance that a random sample won't be representative. Of course if this were to happen it would be because some error (maybe really small) was made on the part of the persons collecting the sample. But it could happen. b. There is always some chance that a random sample won't be representative. But the way that an SRS is taken makes that very unlikely to occur. In essence, "random" means "representative" for all practical purposes. c. There is always some chance that a random sample won't be representative.There is nothing about how an SRS is taken that guarantees it will be representative. In a class with 10 men and 100 women, an SRS of size 10 gives the same chance to all 10 men being chosen as it does to any other sample of size 10. d. There is always some chance that a random sample won't be representative. That having, been said it is very unlikely in the sense that in a class with 10 men and 100 women, an SRS of size 10 being all 10 men would be way less likely than any other sample of size 10.

c. There is always some chance that a random sample won't be representative.There is nothing about how an SRS is taken that guarantees it will be representative. In a class with 10 men and 100 women, an SRS of size 10 gives the same chance to all 10 men being chosen as it does to any other sample of size 10.

2.20: Question 1, Exhibit 1: What is wrong with Statement 1? a. This makes it sound like it is not possible for a probability to be negative b. This makes it sound like the parameter is known in advance c. This makes it sound like the parameter is random d. This makes it sound like the statistic is random

c. This makes it sound like the parameter is random

Quiz 8: Recall the sampling distribution of the sample proportion (page 162 in your book). Specify an interval (range) in which 68% of all sample proportions based on samples of size n could be expected to occur. a. Within (1/sqrt(n)) on either side of the parameter p. b. Within (1/sqrt(n)) on either side of the sample proportion phat. c. Within (0.5)x(1/sqrt(n)) on either side of the parameter p. d. Within (0.5)x(1/sqrt(n)) on either side of the sample proportion phat

c. Within (0.5)x(1/sqrt(n)) on either side of the parameter p.

Quiz 8: You ask a question to a random sample of 1500 adults in Texas (population 18 million people) and to a separate random sample of 500 adults in Indiana (population 5.7 million people). You make separate 95% confidence statements about the percent of all adults in each state who agree. Your margin of error for Indiana is a. smaller than in Texas, because there are fewer people in the Indiana sample. b. the same as in Texas, because the two samples are in the same proportion to their respective population sizes. c. larger than in Texas, because there are fewer people in the Indiana sample. d. may be either smaller or larger than in Texas, because the sample result varies due to chance.

c. larger than in Texas, because there are fewer people in the Indiana sample.

2.22: Question 4, Exhibit 1: If you study 15 hours per week, then how many standard deviations away from the mean do you fall? a. 1 b. Can't tell from information given c. 2 d. 0

d. 0

2.22: Question 2, Exhibit 2 (first part): Use the empirical rule to estimate how likely it is that an answer to this question will be above 4.20. a. 68 chances in 100 b. 84 chances in 100 c. 5 chances in 100 d. 16 chances in 100

d. 16 chances in 100

Quiz 3: If the variance of a set of data is computed to be 4, then the standard deviation is: a. 16 b. Can't tell without having the data c. 4 over square root of n, where n is the number of data points d. 2

d. 2

2.9: What was the Treatment 1 average? a. 3.06 b. 2.16 c. 3.02 d. 2.67

d. 2.67

Quiz 5: A population has 50 items, 21 green and 29 red. Turns out there are 2118760 possible samples of size 5 that can be taken from this population. If the parameter of interest is the true proportion green in the population, what is the parameter in this situation? a. 21/2118760 b. 29/2118760 c. 29/50 d. 21/50

d. 21/50

Quiz 9: Please read the following excerpt a 2006 CNN/USA Today/Gallup poll. Suppose CNN/USA Today/Gallup had wanted to produce a 99.9% confidence interval that had a width of 0.02 (or 2%). What size sample would they have needed to take in order for this to happen? a. 2,500 b. 10,000 c. 6,765 d. 27,060

d. 27,060

2.6: In Exhibit 2, Question 1, you were asked to list all possible distinct samples of size two from this four-person population. How many were there? a. 12 b. 5 c. 3 d. 6

d. 6

Quiz 8: The distribution shown here represents the sampling distribution that resulted from 44 simple random samples, each of size 50, taken from a manufactured population of 250 voters. In each case the proportion of sampled voters who agreed President Trump was doing a good job was recorded. About what percentage of the time did a sample percentage between 21% and 36% occur? a. 50% (either it did or it didn't) b. 84% c. 45% d. 80%

d. 80%

1.12: Exhibit 1, Question 3 - Which data set is more spread out? Why? a. They are spread out almost identically the same. b. Data Set I because the variance is smaller than for Data Set II c. Data Set I because the variance is larger than the standard deviation. d. Data Set I because the variance is larger than for Data Set II

d. Data Set I because the variance is larger than for Data Set II

Quiz 3: Suppose we measured all of your wingspans in class. What would happen to that average wingspan if we added ex-UK player and NBA star Anthony Davis' to the data? a. It would decrease b. It would stay the same since we'd have just one more wingspan and the average would be in the middle c. It would necessarily be greater than the standard deviation of the same data d. It would increase

d. It would increase

2.10: Question 1, Exhibit 1: Explain how you plan to identify the cases for Research Randomizer. a. First randomize the cases based on BAC, then number the rearranged cases from 1 to 296. b. Number the cases from 1 to 73 (the last case number listed).. c. Group the cases based on BAC levels. This will allow you to sample some from each level. d. Number the 296 cases from 1 to 296.

d. Number the 296 cases from 1 to 296.

Quiz 7: Robert Niles is a former mathematics geek turned journalist who is continually trying to educate other journalists about how to interpret statistical arguments. He recently noted "Don't overlook that fact that the margin of error is a 95 percent confidence interval, either. That means that for every 20 times you repeat this poll, statistics say that one time you'll get an answer that is completely off the wall." What does Niles mean by this statement? a. That the "confidence" is in a repeated sampling sense; and to say one gets an interval that is "right" 95% of the time, is to say one will get a "wrong" one 20% of the time.. b. That the "confidence" is in a repeated sampling sense but in reality it is very difficult to actually repeat a sample without human error more than 20 times in a hundred. c. That the "confidence" is in a repeated sampling sense but in reality it is very difficult to actually repeat a sample without human error more than 1 time in 20. d. That the "confidence" is in a repeated sampling sense; and to say one gets an interval that is "right" 95% of the time, is to say one will get a "wrong" one 5% of the time.

d. That the "confidence" is in a repeated sampling sense; and to say one gets an interval that is "right" 95% of the time, is to say one will get a "wrong" one 5% of the time.

1.3: Exhibit 1, Question 1 - The word "doubles" is used in the subheading to describe the increase in cocaine use among children. Look carefully at Table 1.2. Where does the word "doubles" come from? a. The rate for crack was 0.8 in 2006, but 1.60 for Cocaine. 1.6 is double 0.8 so that is where the use of the word "doubles" came from. b. All stimulants were at a rate of about 5.6 in 2001 but cannabis use in 2004 was at a rate of 11.3. 11.3 is essentially double 5.6 and this is where the use of the word "doubles" came from. c. This was just an off-hand way of saying it "increased a lot." d. The article says it doubled from 1% to 2% between 2004 and 2005. But the entry for 2004 is 1.4 and 1.9 for 2005. Good guess that the authors just rounded the 1.4 to 1 and the 1.9 to 2.

d. The article says it doubled from 1% to 2% between 2004 and 2005. But the entry for 2004 is 1.4 and 1.9 for 2005. Good guess that the authors just rounded the 1.4 to 1 and the 1.9 to 2.

1.6: Exhibit 1, Question 1 - We breathe about 15 times per minute, and a hummingbird flaps its wings about 3,000 times per minute. So a rate of 50,000 copies per minute would truly take our breath away and be faster than we could discern with our eyes. Is the 50,000 figure right? a. The figure is correct. 300,000 copies per hour is 300000/6 = 50,000. b. The figure is not correct. 300,000 copies per hour is 300000/60 = 500 a minute not 50,000. That's still a lot but the 50,000 wasn't right. c. The figure is correct. 300,000 copies per hour is 300000/60 = 50000 a minute. That's a lot. d. The figure is not correct. 300,000 copies per hour is 300000/60 = 5000 a minute not 50,000. That's still a lot but the 50,000 wasn't right.

d. The figure is not correct. 300,000 copies per hour is 300000/60 = 5000 a minute not 50,000. That's still a lot but the 50,000 wasn't right.

1.6: Exhibit 2, Question 1 - Is the letter writer correct to claim that the Times overstated the number of cases of domestic violence against women? a. The math isn't correct. An incident every 15 seconds is 4 per minute, 240 per hour, 5760 per day, 40320 per week, 2096640 per year. That's about 210 million, not 21 million. b. The math is correct at least. An incident every 15 seconds is 4 per minute, 240 per hour, 5760 per day, 40320 per week, 2096640 per year. That's about 21 million. c. The math is correct at least. An incident every 15 seconds is 4 per minute, 240 per hour, 5760 per day, 40320 per week, 20,966,400 per year. That's about 21 million. d. The math isn't correct. An incident every 15 seconds is 4 per minute, 240 per hour, 5760 per day, 40320 per week, 2096640 per year. That's about 2.1 million, not 21 million.

d. The math isn't correct. An incident every 15 seconds is 4 per minute, 240 per hour, 5760 per day, 40320 per week, 2096640 per year. That's about 2.1 million, not 21 million.

1.9: Exhibit 2, Question 1 - The referenced article lists three "features of the Constitution that suggest a numerical approach to governance." What is the first one that is listed in the article? a. The Constitution inaugurated a regular and recurring census based on "actual enumeration." b. The framers handled the thorny problem of non-citizen inhabitants by counting slaves at a three-fifths ratio. c. Results of the recurring census would determine not only apportionment in the House and electoral college but also apportionment of direct taxes. d. They chose to erect a representative government that acted on and represented people, not the states.

d. They chose to erect a representative government that acted on and represented people, not the states.

Quiz 2: Recently the Central Kentucky Youth Orchestras started posting rehearsal participation as percentages. So if there are 10 trumpets in an orchestra and 9 showed up to rehearsal, then they'd report a 90% participation rate for trumpets. For sake of simplicity, suppose unbeknownst to the public there are 4 flutes and 10 trumpets. Suppose one flute misses rehearsal and one trumpet misses rehearsal. Would reporting participation results as percentages for each group be potentially misleading? Why or why not? a. No. A 75% rate for flutes and 90% rate for trumpets fairly summarizes that there are more non-compliant flutists than trumpeters. b. No. In each case only one person missed and the participation rates would therefore be the same for flutes and trumpets, making them look equally compliant. c. Yes. In each case only one person missed but the participation rates would be 90% for flutes and 75% for trumpets, making trumpets look less compliant. d. Yes. In each case only one person missed but the participation rates would be 75% for flutes and 90% for trumpets, making trumpets look more compliant.

d. Yes. In each case only one person missed but the participation rates would be75% for flutes and 90% for trumpets, making trumpets look more compliant.

Quiz 7: The University of Kentucky has 21,441 undergraduates, with a gender distribution of 49 percent male students and 51 percent female students. You take a simple random sample of 100 undergraduates (30 males and 70 females) and ask the question "Have you ever attended a date party?" 100% of the males say "yes" and 50% of the females say "yes." If the estimate of all undergraduates who would say "yes" to this question is reweighted to reflect the distribution of males and females in the U.K. population, what would that be in this case? a. about 25% b. about 85% c. about 65% d. about 75%

d. about 75%