Math 105 Final Review

Suppose you want to determine how Americans feel about reality TV. Which of the following samples contains the least amount of bias? A. All the people who phone in their opinion on reality tv to a CBS Evening News call-in poll B. All those people who were randomly selected to receive a reality TV survey in the mail C. People who call the networks during reality TV programs to vote their opinion D. People who respond to an Internet survey at www.realitytv.com

B. All those people who were randomly selected to receive a reality TV survey in the mail

How much can respondents' answers to survey questions change based on simple changes in wording? A. They wont change much at all; changes in wording have little impact on the data B. Answers can change a great deal, even with small changes in wording C. The wording would have to change in a major way, but if it did, the answers would change as well D. None of the above

B. Answers can change a great deal, even with small changes in wording

What motivates a respondent to understate the true response about an undesirable social habit such as smoking? A. Wanting to create deliberate bias B. Desire to please C. Lack of memory D. None of the above

B. Desire to please

What does randomization mean in terms of experiments? A. Each of the experimental units is randomly selected to participate B. Each of the experimental units is randomly assigned to a treatment C. The researchers randomly select which treatments they will include in the experiment D. None of the above

B. Each of the experimental units is randomly assigned to a treatment

What type of statistical error is being made in the following statement? " If this uphill linear trend continues, 50 years from now, one out of every three of us will be an Elvis impersonator." A. Overprediction B. Extrapolation C. Exaggeration D. Expectation

B. Extrapolation

Which of the following statements is true? A. If a data set is skewed to the right, that means there is a bias in the results; the data are higher than they should be B. If a data set is skewed to the right, then the higher vaules are more spread out than the lower vaules C. If a data set is skewed to the right, then the lower vaules are more spread out than the higher vaules D. None of the above

B. If a data set is skewed to the right, then the higher vaules are more spread out than the lower vaules

Which of the following is a research strategy that involves researcher manipulating the participants' environment in some way? A. Sample survey B. Randomized experiment C. Observational study D. None of the above

B. Randomized experiment

If you used a 12-inch ruler to measure the distance across a large pond, which of the following aspects of a good measurement would you be violating? A. Validity B. Reliability C. Unbiased D. None of the above

B. Reliability

Suppose a group of students who reported smoking marijuanna was found to have lower test scores than a group of students who reported they don't smoke marijuanna. What is the most that can be concluded with regard to the population of all students? A. Smoking marijuanna causes lower test scores B. Smoking marijuanna may be related to lower test scores C. Students who smoke marijuanna have lower test scores than students who don't D. None of the above

B. Smoking marijuanna may be related to lower test scores

Suppose a data set is skewed left. What is the most likely relationship between the mean and median? A. The mean is larger than the median B. The mean is smaller than the median C. The mean and the median are not related to each other at all D. The mean and the median are essentially equal

B. The mean is smaller than the median

Suppose on individual in a certain population had a z-score of -2. Which of the following is true? A. This is a bad thing because the individual is below average B. This individual's measurement is 2 standard deviations below the mean C. This individual's original measurement was a negative number D. All of the above are true

B. This individual's measurement is 2 standard deviations below the mean

What does the word 'unit' mean, in a statistical term? A. The unit of measurement that is used (for example feet, inches, etc.) B. The people doing the sampling are called the sampling unit C. A single individual or object to be measured D. None of the above

C. A single individual or object to be measured

{Babysitting Narrative} Which of the following describes the population for this example A. The 1,000 teenagers who participated in the study B. All teenagers in the U.S. who do babysitting for extra money C. All teenagers in the U.S. D. The 33% of teenagers who do babysitting to earn extra money

C. All teenagers in the U.S.

Which of the following would give a news reporter the best and most comprehensive foundation for a news story involving a statistical study? A. A press release gives everything they need because it's written just for them B. Another newspaper article written by the competitor C. An article in a peer-reviewed scholarly, accompanied by a press release D. A conference presentation given by the researchers themselves

C. An article in a peer-reviewed scholarly, accompanied by a press release

Which of the following is necessary to conduct a study properly? A. Get a small sample B. What criteria is needed in a case study C. Decide whether or not the study should be an observational study or a randomized (controlled) experiment D. All of the above

C. Decide whether or not the study should be an observational study or a randomized (controlled) experiment

Which of the following is a well worded survey question for determining a voter's opinion on a tax increase for education? A. Would you be willing to agree to a small tax increase that would help the education of our children? B. Do you agree with a tax increase for education? C. How do you feel about a tax increase for education (agree, disagree, neutral)? D. All of the above are well worded questions

C. How do you feel about a tax increase for education (agree, disagree, neutral)?

Assuming there is a statistical relationship between height and weight for adult females, which of the following statements is true? A. If we knew a woman's height, we could predict her weight B. If we knew a woman's height, we could determine the exact weight for all women with that same height C. If we knew a woman's height, we could predict the average weight for all women with that same height D. All of the above

C. If we knew a woman's height, we could predict the average weight for all women with that same height

If two measurement variables are both found to be changing over time, what does this mean? A. It means there is a casual link between the two variables B. It means there is a common cause of the changes in both variables (possibly other than time) C. It means that even though the two variables may be highly correlated, they could be completely unrelated in terms of cause and effect D. None of the above

C. It means that even though the two variables may be highly correlated, they could be completely unrelated in terms of cause and effect

Suppose you want to find out how much money each adult will spend on Valentine's Day this year, on average. {Valentine spending narrative} Suppose you are a DJ of a local radio station, so you ask people to call in with their responses. What type of sample are you getting here? A. A self-selected sample B. A convenience sample C. A cluster sample D. A systematic sample

A. A self-selected sample

Statistical relationships such as correlation are useful for describing features of _______________. A. An aggregate or population B. An individual from the population C. A sample from the population D. All of the above

A. An aggregate or population

Which of the following describes an experiment? A. Create differences in the explanatory variable and then examine the results B. Observe differences in the explanatory variable and then notice whether these are related to differences in the response variable C. Both A. and B. are experiments D. Neither A. nor B. are experiments

A. Create differences in the explanatory variable and then examine the results

Which of the following cannot be obtained from observational studies? A. Definitive evidence of casual connection B. A reasonable explanation for casual connection C. Any evidence of a casual connection D. Definitive evidence of a correlation

A. Definitive evidence of casual connection

A survey question that starts out with the phrase "Do you agree that..." is an example of what? A. Deliberate bias B. Unintentional bias C. Response bias D. Convenience bias

A. Deliberate bias

When you read the results of a scientific study, which of the following should you do first? A. Determine which type of research strategy was used (observational study, randomized experiment, etc.) B. Look at the results and decide whether they make sense or not C. Jump to the where they show the data, and see if it was collected properly D. Decide if the results apply to your life

A. Determine which type of research strategy was used (observational study, randomized experiment, etc.)

How important is the wording of the question in terms of getting a good measurement in a survey or experiment? A. Extremely important. Poorly worded questions can lead to bias and inaccuracy. B. Only somewhat important; it's the essence of the issue that matters. C. It shouldn't matter at all. A question is a question. D. It depends on the situation.

A. Extremely important. Poorly worded questions can lead to bias and inaccuracy.

Which of the following does not require the data to be ordered before you can get the right answer? A. Mean B. Median C. Quartiles D. Range E. All of the above require the data to be ordered

A. Mean

Which of the following is implemented in an experiment to reduce unknown systematic biases due to confounding variables that might otherwise exist between treatment groups? A. Randomization B. Block C. Repeated measures D. All of the above

A. Randomization

Which of the following is not true about the subject of statistics? A. Statistics only represents numbers that are used for a specific purpose B. Statistics is a collection of procedures and principles for dealing with information C. Statistics appears in your everyday life D. Statistics has a great deal to do with decision making in the face of uncertainty

A. Statistics only represents numbers that are used for a specific purpose

If the width of a box in a boxplot is very large, compared to the rest of the boxplot, what does that mean about the shape of the data set A. The data are very spread out in the middle B. The data are clumped tightly in the middle C. The data are not symmetric D. Not enough information to tell

A. The data are very spread out in the middle

What impact can non-respondents have on survey results? A. The non-respondents will have a negative impact; the results of the survey will be biased toward the opinions of the respondents B. The non-respondents will have no effect because they didn't respond to the survey C. The non-respondents will have a positive impact; without them, the results of the survey will be more dramatic and more likely to be picked up by the news media D. None of the above

A. The non-respondents will have a negative impact; the results of the survey will be biased toward the opinions of the respondents

What is the biggest problem with having open questions on a survey or in an experiment? A. The participants' responses are difficult to summarize or categorize. B. You have to worry more about how an open question is worded than how a closed question is worded C. There is no problem with open questions; they provide the most accurate information about how a person really feels D. None of the above

A. The participants' responses are difficult to summarize or categorize.

If you tried to measure happiness y using an IQ test, which of following aspects of a good survey measurement would you be violating? A. Validity B. Reliability C. Unbiased D. None of the above

A. Validity

Which of the following is a true statement? A. You can't totally eliminate bias in a study, no matter what you do B. If you do everything right, you will come out with the right conclusion every time when using statistics C. You don't need all seven of the components of a good study in order to be confident in your results; you only need most of them D. All of the above are true statements

A. You can't totally eliminate bias in a study, no matter what you do

Suppose a recent election exit pollster reports that "Forty-eight % of the voters polled said they voted for Candidate A. The margin of error for this survey is plus or minus 2.5% points." Assume the exit poll was designed and conducted correctly. {Exit poll narrative} About how many people were sampled? A. 40 B. 1,600 C. 16,000 D. Not enough information to tell

B. 1,600

Suppose you want to find out how much money each adult will spend on Valentine's Day this year, on average. {Valentine spending narrative} Suppose you go to a local mall the day before Valentine's Day and ask the first 50 people you see. What type of sample are you getting here? A. A self-selected sample B. A convenience sample C. A cluster sample D. A systematic sample

B. A convenience sample

What type of sample would give the most unbiased data? A. A volunteer response sample B. A random sample C. A sample with a high number of respondents D. None of the above

B. A random sample

Which of the following situations will produce the most accurate results? A. A simple random sample of 3,500 people with a 10% response rate (350 responses) B. A simple random sample of 500 people with a 70% response rate (350 responses) C. A convenience sample of 350 people with a 100% response rate (350 responses) D. They would all produce the same level of accuracy since each had 350 responses

B. A simple random sample of 500 people with a 70% response rate (350 responses)

Which of the following statements is statistically correct? A. "Jimmy is taller than normal for a two-year old" B. "Jimmy is taller than the average two-year old" C. "Jimmy is taller than the average height of two-year olds" D. All of the above are statistically correct

C. "Jimmy is taller than the average height of two-year olds"

Which of the following is an example of an open question? A. "Which of the following four issues do you feel is the most important problem facing this country today? If you prefer, you may name a different problem as most important; simply choose 'other' and explain your answer." (Four choices plus 'other') B. "Don't you think it's time that we faced the fact that unemployment is the biggest problem facing this country today?" (Choices are yes, no, and non opinion) C. "What do you feel is the most important problem facing this country today?" (Fill in the blank) D. None of the above

C. "What do you feel is the most important problem facing this country today?" (Fill in the blank)

Most researchers are willing to declare that a relationship is statistically significant if the chances of observing the relationship in the sample when actually nothing is going in the population are less than what percent? A. 95% B. 50% C. 5% D. None of the above

C. 5%

Suppose a recent election exit pollster reports that "Forty-eight % of the voters polled said they voted for Candidate A. The margin of error for this survey is plus or minus 2.5% points." Assume the exit poll was designed and conducted correctly. {Exit poll narrative} What can be concluded about Candidate A? A. 48% of all voters will vote for Candidate A B. We are confident that between 45.5% and 50.5% of all voters will vote for Candidate A. This means he/she will win the election because 50.5% is more than half of the votes C. We are confident that between 45.5% and 50.5% of all voters will vote for Candidate A. The election is "too close to call" at this point. It could go either way D. None of the above

C. We are confident that between 45.5% and 50.5% of all voters will vote for Candidate A. The election is "too close to call" at this point. It could go either way

Which of the following can get in the way of concluding a causal connection between two measurement variables? A. A weak correlation B. An observational study C. Confounding variables D. All of the above

D. All of the above

Which of the following influences on the experimental units can bias the results of an experiment? A. Placebo effect B. Hawthorne effect C. Not being blinded D. All of the above

D. All of the above

Which of the following is a potential complication of observational studies? A. Confounding variables B. The improper conclusion of causation C. Improper extension of the results D. All of the above

D. All of the above

Which of the following is not an example of a situation involving statistics? A. A pie chart showing the % of males and females in your class B. A designed experiment comparing the heights of right-handed and left-handed people C. A survey asking your opinion of whether or not college football players should be paid to play football D. All of the above

D. All of the above

Which of the following studies can result in researchers extending the results inappropriately because the sample doesn't represent the intended population? A. Studies involving volunteers (self-selected samples) B. Studies involving convenience samples C. Case-control studies D. All of the above

D. All of the above

Which of the following is not a measure of spread or variability in a data set? A. Standard deviation B. IQR C. Range D. All of the above are statistically correct

D. All of the above are statistically correct

Which of the following statements is correct about the standard normal table? A. The table always the portion of the population below the z-score B. The table will give you the percentile below your score C. The table gives you a value between 0 and 1 D. All of the above are statistically correct

D. All of the above are statistically correct

Which of the following is not true about placebos? A. Placebos can be very effective in producing a response B. Placebos are only useful if the subject is blind as to whether or not they receive one C. Participants assigned a placebo are part of the control group of an experiment D. All of the above are true statements

D. All of the above are true statements

Which of the following is true about statistics? A. Numbers don't lie. All statistics have to be believed B. Statistics can be made to say whatever you want them to say. No statistic should be believed. C. Any statistic that is based on data is likely to be correct. D. All statistics should be carefully scrutinized before determining whether or not they can be believed. Some are correct some are not.

D. All statistics should be carefully scrutinized before determining whether or not they can be believed. Some are correct some are not.