Stats:)

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)?

2 in 6

The heights of male students is normally distributed with a mean of 170 cm and a standard deviation of 8 cm. Find the percentage of male students whose height is above 186 cm

2.5%

Use the following data set: 15, 11, 18, 14, 14, 13, 17, 18 Calculate the Standard deviation

2.51

A recent study of 150 recent college graduates finds that 125 are employed. Please use 80% Level of Confidence. If we were to take 200 samples of 150 students, how many (give a count) of the Confidence Intervals would we anticipate to NOT contain the parameter?

40

The heights of male students is normally distributed with a mean of 170 cm and a standard deviation of 8 cm. Find the percentage of male students whose height is bellow 170 cm?

50%

A recent study has shown that 39% of a poll of 416 US parents say they get frustrated by technology because "it makes it hard to have conversation" with their children. The 416 US parents make up the

sample

The statistical term for the fact that the value of a statistic will vary from sample to sample when simple random samples are chosen is

sampling variability

Which of the following sources of error is addressed by the margin of error?

sampling variability that comes from choosing a random sample

An MSNBC article on August 19, 2005, by Alex Johnson reported the results of a poll taken on two different, but demographically equivalent groups of high school students at roughly the same time. By overwhelming majorities, students said they would work harder at their studies if more was expected from them-65 percent in one of the polls and 88 percent in the other. This difference between the 65% and the 88% is called:

sampling variability; it's the reason we need a margin of error when conducting polls

A recent study has shown that 39% of a poll of 416 US parents say they get frustrated by technology because "it makes it hard to have conversation" with their children. In this situation, 39% is the

statistic

The student newspaper runs a weekly question that readers can answer online or by campus mail. One question was "Do you think the college is doing enough to provide student parking?" Of the 100 people who responded, 79% said "No" The number 79% is a:

statistic

Which one is NOT an example of why inference is not easy.

Inference is impossible because it is up to the interpretation of the person

Careful CountingThe audio segment above ends with Charlie McDonnell (of the British "Fun Science" videos) noting that "every now and then, at random, you end up with something awesome." We might take that to mean that every now and then, a simple random sample is representative of a population with respect to a certain list of demographics. Let's look at a simple example to see how likely that might be. Suppose you have a population with two men—one a Republican and one a Democrat; and two women—one a Republican and one a Democrat. There are six possible distinct samples of size two from this four-person population. If M = male, F = female, R = Republican, and D = Democrat, then the possible samples are:

(MR, MD), (MR, FR), (MR, FD), (MD,FR), (MD, FD), (FR,FD)

What two value is the correlation coefficient always between?

-1 and 1

Please use the data set on page 36 and answer the following question: What is the coefficient of variation for this group of eleven persons?

.10

Use the table on page 35 in your textbook and answer the following question: What is the coefficient of variation for this group of ten person?

0.05

Use the following data set: 15, 11, 18, 14, 14, 13, 17, 18 Calculate the coefficient of Variation

0.17

A major metropolitan newspaper selected a simple random sample of 1,600 readers from their list of 100,000 subscribers. They asked whether the paper should increase its coverage of local news. Forty percent of the sample wanted more local news. What is the 99% confidence interval for the proportion of readers who would like more coverage of local news?

0.37 to o.43

The UK basketball team reported the following statistics for FGM: Field Goals Maid in 2019. Find the coefficient of variation for the number of Field Goals Made (FGM). 138, 163, 150, 107, 71, 56, 58, 23,29

0.597

What is the Overall Accuracy)? Note: Overall Accuracy=Prevalence*Sensitivity+(1-Prevalence)* Specificity Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

0.65

A recent study of 150 recent college graduates finds that 125 are employed. What is the 80% Confidence interval? (z*=1.28)

0.83+/-0.06

Assume there are ten possible pairs of days an employee could pick from, and that list of the sets of ten pairs suggested in the question above is the right one. If a pair was just picked at random, what is the chance that they'd pick Monday and Friday as the pair, and does this suggest the secretary (in the amended dialogue) has uncovered a bias?

1 in 10. Yes, if 40% are choosing Monday and Friday, that is evidence of bias toward that pair.

For a simple random sample of size two, all samples of size two have the same chance of being chosen. What would the likelihood be of choosing any one of these samples?

1 in 6

Nursing Knowledge Needed On June 2, 2007, a nurse in Wales accidentally injected an 85-year-old patient with a lethal amount of insulin during a home visit. While the syringes used to inject insulin are typically marked with insulin units instead of the usual milliliters, this nurse found herself without an insulin syringe on hand. So she retrieved a common syringe from her car and proceeded to do the transformation from milliliters to insulin units in her head. If 1 milliliter equals 100 insulin units, how many milliliters should the patient have been given if she had been prescribed 36 units?

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.

When a simple random sample of size n is chosen, the margin of error for 95% confidence is

1/(sqrt (n))

Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 175 10 185 Drunk (OSL≥5) 20 15 35 Totals 195 25 220 For the data above what is the FNR (False negative Rate ) for this test?

10/25

Use the following data set: 15, 11, 18, 14, 14, 13, 17, 18 Find the Meadian

14.5

Use the following data set: 15, 11, 18, 14, 14, 13, 17, 18 Calculate the Mean

15

Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 175 10 185 Drunk (OSL≥5) 20 15 35 Totals 195 25 220 Please have a look at the data provided. What is the Sensitivity for this test?

15/25

The price for a ticket at Carmike Movie theater in Lexington changed from 1.00$ in year 2000 to 2.50$ in year 2014. Calculate the percent of change from year 2000 to year 2014.

150%

Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 175 10 185 Drunk (OSL≥5) 20 15 35 Totals 195 25 220 Look at the data above. What is the Specificity for this test?

175/195

I would like to spend a summer in France after I graduate. I am worried that this will be too expensive because the dollar buys fewer French francs now. When I entered college, a dollar was worth 6.5 francs. Now a dollar is worth only 5.25 francs. By about what percent has the value of the dollar in francs decreased?

19%

Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 175 10 185 Drunk (OSL≥5) 20 15 35 Totals 195 25 220 Look at the data above. What is the FPR (False Positive Rate) for this test?

20/195

What is the FPR (False Positive Rate)? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

20/55

In January of 2012, the price of Target common stock rose from $131 per share to $162 per share. What percent increase is this?

23.7%

Please read Beyond the Numbers 2, page 29 and answer the question: The "previous school year" being referred to is the 2010-11 year. What was the total number of shootings during the 2010-11 school year?

261

Twenty-four students were fatally shot during the school year that ended June 15, 2012, four fewer than in 2010-2011 school year. But the overall shooting toll, 319, was the highest in four years and a nearly 22 percent increase from the previous school year. What was the total number of shootings during the 2010-2011 school year?

262

What is the FNR (False negative Rate)? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

27/81

Nine hundred (900) high school freshmen were randomly selected for a national survey. Among survey participants, the mean grade-point average (GPA) was 2.7, and the standard deviation was 0.4. What is the margin of error, assuming a 95% confidence level?

3.3%

Consider the result of a fictional Stat 100 final exam taken by 120 students, as given in thefollowing relative frequency distribution:Grade Less than 50 50-59 60-69 70-79 80-89 90-100Cumulative Frequency 15% 10% 30% 25% 15% 5% GradeLess than 5050-5960-6970-7980-8990-100Cumulative Frequency15%10%30%25%15%5% How many students received less than a 60 on this exam?

30

Have a look at the following table where we have classified all corrective lens wearers by age and type. Below 20 years old Above 20 years old Eyeglasses only (millions) 43.3 54.6 Contact lenses (millions) 22.9 7.0 TOTAL 66.2 61.6 From the table, 11.4% of above 20 years old corrective lens wearers wear contact lenses. The corresponding percentage for below 20 years old is

34.6%

What is the Specificity rate? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

35/55

What is the NPV (Negative Predictive Value)? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

35/62

Read the following extract from the article and answer the next 2 questions. A bare majority of Americans support President Obama's plan to send 30,000 more troops to Afghanistan, but many are skeptical that the United States can count on Afghanistan as a partner in the fight or that the escalation would reduce the chances of a domestic terrorist attack, according to the latest New York Times/CBS News poll. ... The support for Mr. Obama's Afghanistan policy is decidedly ambivalent, and the nation's appetite for any intervention is limited. Over all, Americans support sending the troops in by 51% to 43%, while 55% said setting a date to begin troop withdrawals was a bad idea....The poll was conducted by telephone from Friday through Tuesday night, with 1,031 respondents, and has a margin of sampling error of plus or minus three percentage points. Question: About how many people in the sample supported sending more troops to Afghanistan?

51% of 1,031 which is about 526 people

Please read below or page 106 Beyond the Numbers 1 prompt. Use this information for the next 3 questions. (You do not need to read the whole article. Information provided is enough to answer the questions. ) uthors: Robert Jones, Daniel Cox, and Juhem Navarro-RiveraSource: http://publicreligion.org/site/wp-content/uploads/2014/02/2014.LGBT_REPORT.pdf (Links to an external site.) The following is an excerpt from the Executive Summary of this report: Support for same-sex marriage jumped 21 percentage points from 2003, when Massachusetts became the first state to legalize same-sex marriage, to 2013. Currently, a majority (53%) of Americans favor allowing gay and lesbian couples to legally marry, compared to 41% who oppose. In 2003, less than one-third (32%) of Americans supported allowing gay and lesbian people to legally marry, compared to nearly 6-in-10 (59%) who opposed. Near the end of the report, the authors add: Results of the survey were based on bilingual (Spanish and English) telephone interviews conducted between November 12, 2013 and December 18, 2013, by professional interviewers under the direction of Princeton Survey Research Associates. Interviews were conducted by telephone among a random sample of 4,509 adults 18 years of age or older in the entire United States (1,801 respondents were interviewed on a cell phone, including 977 without a landline phone). The margin of error is +/- 1.7 percentage points for the general sample at the 95% confidence level. In addition to sampling error, surveys may also be subject to error or bias due to question wording, context, and order effects. Question: Using the MOE given in the article, what is the 95% confidence interval for the true proportion of Americans in favor of allowing gay and lesbian couples to marry.

51.3% to 54.7%

The UK basketball team reported the following statistics for FGM: Field Goals Maid in 2019. Find the standard deviation for the number of Field Goals Made (FGM). 138, 163, 150, 107, 71, 56, 58, 23,29

52.735

Consider the result of a fictional STA 210 final exam taken by 120 students, as given in thefollowing relative frequency distribution: GradeLess than 5050-5960-6970-7980-8990-100Cumulative Frequency15%10%30%25%15%5% How many students received at least a 70 on this exam?

54

What is the PPV (Positive Predictive Value)? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

54/74

What is the Sensitivity Rate? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

54/81

NEW YORK (Reuters Health)-Orthopedic surgeons are much more hesitant to see kids with broken bones than they were a decade ago, suggests new research from California. When contacted by telephone, more than half (58%) of orthopedic practices wouldn't schedule an appointment for a kid with a recently-broken arm who had private insurance. What is the statistic?

58% of orthopedic practices wouldn't schedule an appointment for a kid with recently-broken arm who had private insurance

A recent poll of 1500 college-age students found that 885 agreed with U.S. foreign policy toward Israel. What is the corresponding 80% confidence interval?

59% plus or minus 2%

Use the following data set: 15, 11, 18, 14, 14, 13, 17, 18 Calculate the Variance

6.3

Weighting Room In 2012, the National Journal reported: "Critics allege that pollsters are interviewing too many Democrats—and too few Republicans or independents—and artificially inflating the Democratic candidates' performance." Suppose a simple random sample of voters yielded the following poll results: Use the following table to answer next 3 questions Planned to Vote "Obama"Planned to Vote "Romney"80 Democrats70%30%20 Republicans20%80% Question: What proportion of likely voters overall (Democrats and Republicans combined) planned to vote for Barack Obama?

60%

Please use the data set on page 36 and answer the following question: What is the median of this data set?

67

Use the data table on page 35 in your textbook and answer the following question: What is the median wingspan for this group of ten persons?

67

Winging Out Some Computations Your wingspan is the distance from the tip of the middle finger on your left hand to the tip of the middle finger on your right, with your arms parallel to the ground. The wingspans of 10 hypothetical individuals are recorded in the table page 35 in your textbook. What is the mean wingspan for this group of ten persons?

67.2

A BIGS Change Suppose the former Kentucky basketball great and subsequent NBA star Anthony Davis drops in for a visit and joins the group of 10 persons in the data set introduced first in the problem above. Please use the data set on page 36 and answer the following question: What is the mean of this new eleven-person data set?

69.1

Use the following data set: 15, 11, 18, 14, 14, 13, 17, 18 Find the Range of the data

7

The UK basketball team reported the following statistics for FGM: Field Goals Made in 2019. Find the median for the number of Field Goals Made (FGM). 138, 163, 150, 107, 71, 56, 58, 23,29

71

74% of the 398 student who attended the October 15th lecture said they know how to "explain correctly a confidence statement". If these 398 were a simple random sample drawn from the entire UK student population, what would a 95% confidence interval be for the percent of all students who could do likewise?

74%+/-5%

The student newspaper runs a weekly question that readers can answer online or by campus mail. One question was "Do you think the college is doing enough to provide student parking?" Of the 100 people who responded, 79% said "No". What is the 95% Confidence Interval?

79%+/-10%

The heights of male students is normally distributed with a mean of 170 cm and a standard deviation of 8 cm. Find the percentage of male students whose height is between 162 cm and 186 cm

81.5%

What is the Prevalence? Outcome of Field Sobriety Test Actual Condition: Sober (No goggles or White Goggles) Actual Condition: Drunk (Red or Black Goggles) Totals Sober (OSL<5) 35 27 62 Drunk (OSL≥5) 20 54 74 Totals 55 81

81/136

Versions of the following completely-made-up story have been told elsewhere. Suppose there are exactly 9 people on a bus in Seattle, and the average of their yearly incomes is $65,000. At the next stop, the highest paid person on the bus (with an income of $120,000 per year) gets off, and Bill Gates gets on. Mr. Gates makes 7.6 billion dollars a year. Please answer the next 3 questions using this scenario. Question: What is the new average salary of people on the bus?

844,496,111.10

The UK basketball team reported the following statistics for FGM: Field Goals Made in 2019. Find the mean for the number of Field Goals Made (FGM). 138, 163, 150, 107, 71, 56, 58, 23,29

88.333

Use the data table on page 35 in your textbook and answer the following question: What is the variance for this group of ten persons?

9.29

The heights of male students is normally distributed with a mean of 170 cm and a standard deviation of 8 cm. Find the percentage of male students whose height is between 154 cm and 186 cm

95%

What is the definition of the placebo effect?

A real response from subjects to a fake treatment.

What is meant by a heterogeneity sample?

A sample designed to capture diversity across subgroups.

Define what is meant by an expert sample?

A sample designed to capture opinions that are especially informed on the topic of interest.

For the next 4 questions, please do your own search and then pick the best answer. What is meant by a convenience sample?

A sample that is chosen because the subjects are easily accessed.

What is meant by a snowball sample?

A sample where the initially chosen subjects are asked to collect data from other subjects they choose, and then those other subjects have to recruit others.

The following is an excerpt from Gallup's website describing their Daily Tracking Survey. The page was last available at http://www.gallup.com/174155/gallup-daily-tracking-methodology.aspx (Links to an external site.) Use it to answer next 2 questions Gallup interviews U.S. adults aged 18 and older living in all 50 states and the District of Columbia using a dual-frame design, which includes both landline and cellphone numbers. Gallup samples landline and cell phone numbers using random-digit-dial methods. Gallup purchases samples for this study from Survey Sampling International (SSI). Gallup chooses landline respondents at random within each household based on which member had the next birthday. Each sample of national adults includes a minimum quota of 50% cellphone respondents and 50% landline respondents, with additional minimum quotas by time zone within region. Gallup conducts interviews in Spanish for respondents who are primarily Spanish-speaking. What is the actual population being addressed by a Gallup telephone survey?

Adults 18 years and older, living in the United States.

NEW YORK (Reuters Health)-Orthopedic surgeons are much more hesitant to see kids with broken bones than they were a decade ago, suggests new research from California. When contacted by telephone, more than half (58%) of orthopedic practices wouldn't schedule an appointment for a kid with a recently-broken arm who had private insurance. What is the population in this study?

All orthopedic practices

What is correct about claim from Science that a CA. field that produced 750,000 melons per acre, where 1 acre=43,560 square feet.

Doing the math means that there were over 17 melons per sq. ft.but this is too many

A survey was conducted by Playboy, asking questions about the sex lives of 5,000 U.S. University and College students. One question asked: "Are you in a nude picture on someone's camera phone?" 24 percent said "Yes". Name the error you'd expect this survey to suffer from even if all 15.9 million College and University students in the U.S. had answered, and not just 5,000.

Error caused by false responses

Suppose you have 113 Friends on Facebook and you want to choose a simple random sample of 20 of them. Describe in detail how you would select your simple random sample.

First I would assign each of my friends a number starting with my first friend being number one, second friend being number two and so on. Then I would use a random number generator to randomly select 20 numbers and each number would have a corresponding friend.

The same Gallup Poll asked its 1523 adult respondents and also 501 teens (ages 13 to 17) whether they generally approved of legal gambling: 63% of adults and 52% of teens said yes. The margin of error for 95% confidence statement about teens would be

Greater than for adults, because the teen sample is smaller.

Answer the next 3 questions while watching the "Split Brain" video atSplit brain behavioral experiments (Links to an external site.) If video doesn't open here please check out the link on Problem 4 page 9 in your text. You may also "google" it. Question: When Joe was shown the pan in his left visual field, what did he say he saw?

He said he didn't see anything.

Answer the following question while watching the "Split Brain" video athttp://www.youtube.com/watch?v=ZMLzP1VCANo (Links to an external site.) Question: When Joe was shown the saw in his left visual field and a hammer in his right visual field, what did he say he saw?

He said he saw a hammer

Answer the following question while watching the "Split Brain" video atSplit brain behavioral experiments (Links to an external site.) Question: When Joe was shown the saw in his left visual field and the hammer in his right, what was he able to draw with his left hand?

He was able to draw a saw

Suppose we construct a histogram of these twelve "Murders" values. We choose the smallest bin to have 420 as a left endpoint and use a bin width of 50. Which of the following has to be the result? Please have a look at page 30 graphs and choose the correct answer.

II

If you keep the confidence level the same, but increase the sample size from 10 to 100, what happens to the margin of error?

It gets smaller

An advertisement for a new heartburn treatment says that it "reduces heartburn by 300 percent." What does this mean?

It's nonsense, because removing 100 percent of the heartburn already removes all of it.

What is the primary advantage the median enjoys over the mean?

Less sensitive to extreme values

The small data set bellow shows the pay rate for 10 employees in a coffee shop. Which statistics will you use for measuring the center of the data set, that is not affected from the outlier. 13$ 13$ 13.50$ 13.50$ 250$ 13$ 13.50$ 13.30$ 13.20$ 13.70$

Median

Which of the following statements do you think could possibly be true?

More than 30 million people live in California

One of the 9 people on the bus was a snoozing journalist who 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 create an inaccurate inference regarding the typical income of Seattle residents? Why?

Most residents of Seattle will make a lot less than Mr. Gates, so the reported mean will be an exaggeration.

Following are data on the populations and numbers of death row prisoners for several states. State Population Death Row prisoners California 28 168 247 Florida 12 377 294 Illinois 11 544 120 Nevada 1 060 45 Which state has the highest number of death row prisoners relative to the size of its population?

Nevada

Please read Beyond the numbers , Problem 1 on page 27 , and then answer the question. Question: Is the 50,000 figure right?

No. 300000/60 = 5000, not 50000.

A letter to the editor of the New York Times complained about a Times editorial that quoted the following demoralizing statistic:An American woman is beaten by her husband or boyfriend every 15 seconds. The writer of the letter complained: "At that rate, 21 million women would be beaten by their husbands or boyfriends every year. That is simply not the case."Is the letter writer's numerical reasoning correct?

No. An incident every 15 seconds is 4 per minute, 240 per hour, 5760 per day, 40230 per week, 2096640 per year which is about 2.1 million, not 21 million.

In the Executive Summary, the authors state that "a majority (53%) of Americans favor allowing gay and lesbian couples to legally marry..."Were all Americans asked? How could the statement be changed so that it more precisely reflects the inference based on the sample data?

No. Could say the sample suggests a majority of Americans favor ...

Suppose you were to take another random sample of Americans at the same point in time and ask the same question. Would you find-without question-that more than 50% of the respondents were in favor of allowing gay and lesbian couples to marry? Why or why not?

No. That's sampling variability.

The Department of Statistics at University of Kentucky surveyed 1111 students asking them the following question: "How many cars your Family own?" This is an example of:

Numerical-Discrete Variable

Do you think the proportion you provided above is an underestimate, overestimate, or neither?

Overestimate

A list of the over 2300 Henry Clay High School Students is compiled. From that list 250 names are randomly chosen and given a survey to complete. Of those surveyed 72% said they intended to attend college after completing high school. What would the percentage of all Henry Clay High School students that plan to attend college be an example of?

Parameter

Which of the following is correct?

Parameters describe population characteristics.

A list of the over 2300 Henry Clay High School Students is compiled. From that list 250 names are randomly chosen and given a survey to complete. Of those surveyed 72% said they intended to attend college after completing high school. What would all 2300 plus Henry Clay High School students be an example of?

Population

What are the population and the parameter?

Population is all Americans. Parameter would be the true proportion of all Americans who accept scientific evidence of global warming, if it were possible to ask all Americans.

The Department of Statistics at University of Kentucky surveyed 1111 students asking them the following question: "What is your major?" This is an example of:

Qualitative Variable

What was VIP doing to boost the ratings of its Kindle Fire cover?

Reimbursing customers for the cover if they posted a review.

A list of the over 2300 Henry Clay High School Students is compiled. From that list 250 names are randomly chosen and given a survey to complete. Of those surveyed 72% said they intended to attend college after completing high school. What would the 250 students surveyed would be and example of?

Sample

Match these scatterplots with their description.

Scatterplot A) Weak Neg Scatterplot B) Strong Pos Scatterplot C) Weak Pos Scatterplot D) Strong Neg Scatterplot E)No ass

What is the simplest method of sampling fairly?

Simple Random Sampling

A list of the over 2300 Henry Clay High School Students is compiled. From that list 250 names are randomly chosen and given a survey to complete. Of those surveyed 72% said they intended to attend college after completing high school. What would the 72% that plan to attend college be an example of?

Statistic

A survey is conducted on students taking a statistics class. Several variables are measured in the survey. Which of these variables listed below is not quantitative?

Student's major

An example of a categorical variable is

Teacher hair color

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 will get an answer that is completely off the wall." What does Niles mean by this statement?

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

NEW YORK (Reuters Health)-Orthopedic surgeons are much more hesitant to see kids with broken bones than they were a decade ago, suggests new research from California. When contacted by telephone, more than half (58%) of orthopedic practices wouldn't schedule an appointment for a kid with a recently-broken arm who had private insurance. What is the parameter?

The % of all orthopedic practices wouldn't schedule an appointment for a kid with recently-broken arm who had a private insurance

In the food coloring cancer experiment, what were the subjects?

The 500 rats

NEW YORK (Reuters Health)-Orthopedic surgeons are much more hesitant to see kids with broken bones than they were a decade ago, suggests new research from California. When contacted by telephone, more than half (58%) of orthopedic practices wouldn't schedule an appointment for a kid with a recently-broken arm who had private insurance. What is the sample?

The Orthopedic practices that were contacted by phone

The VIP brand Kindle Fire cover received 4,945 reviews on Amazon by early 2012, averaging a nearly perfect 4.9 stars out of five. That's quite impressive. It is tempting to think that online reviews, especially those posted at major sites like Amazon, are representative of consumer experiences. We know, however, that voluntary responses are often biased. But are product reviews even less accurate than previously thought? In his 2012 Time article "9 Reasons Why You Shouldn't Trust Online Reviews," Brad Tuttle writes, "You shouldn't believe everything you read. And if you're reading online reviews of products, hotels, restaurants, or local businesses or services Is this cited correctly? Then you should believe even less." You can find Tuttle's article online at http://business.time.com/2012/02/03/9-reasons-why-you-shouldnt-trust-online-reviews/ (Links to an external site.) . Question: There are several reasons listed in the article as to why you should be very cautious about online reviews. Which one of the following is not one of the first three reasons listed in the article?

The Russians are known to plant positive reviews for socially detrimental consumer goods.

Please read Beyond the Numbers Question 1 on page 6 in your text. Take your time and when you feel ready please pick the best answer to the question: The word "Doubles" is used in the subheading to describe the increase in cocaine use among children. Look carefully at table 1.1 (page 7). Where does the word " doubles" come from?

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.

Speaking of violence in Chicago, the table below shows the number of murders in Chicago from 2001 through 2012. Find the mean and the median number of murders over this time period. YEAR2001 20022003200420052006200720082009201020112012Murders667656601453451471448513459436435506

The mean is 508 and median is 465.

In what sense can a random-digit-dial sample be thought of as a simple random sample?

The numbers are selected at random, by a computer, for all working exchanges.

A survey in a local newspaper stated that of the individuals who frequent bookstores, 14% were buying books and 28% were not. What is wrong with this picture?

The percentages only add up to 42%. It should be 100%

Read the following extract from the above article and answer the related questions to see if you understand the data. The public overwhelmingly supports the prohibition of text messaging while driving, the latest New York Times/CBS News poll finds. Ninety percent of adults say sending a text message while driving should be illegal, and only 8% disagree. ... The Times/CBS News telephone poll was conducted September 19-23 with 1,042 adults nationwide and has a margin of sampling error of plus or minus three percentage points. QUESTION: How was the sample taken, and what was the result of the survey?

The poll was a telephone poll and 90% of the sample said sending a text message while driving should be illegal.

In the food coloring cancer experiment, what is one obvious source of confounding?

The rats were mixed with the control leaving it hard to tell which rats got the Red No. 2 and which did not.

What is the new median salary of people on the bus?

The same as above

The name of the pattern of values that a statistic takes when we sample repeatedly from the same population is

The sampling distribution of the statistic

Reporting the results of a medical experiment, researchers claim that the difference between two headache treatments is "statistically significant." What does this mean?

There is a difference between the two treatments

How well did people perform in spotting fake reviews?

They were right about 50% of the time.

A sportswriter wants to know how strongly Lexington, Kentucky residents support building a new arena for the UK basketball team. She stands outside Rupp Arena before a game and interviews the first 45 people who enter the stadium. The newspaper asks you to comment on their survey of local opinion. You say

This is not a simple random sample. It will almost certainly overestimate the level of support among all Lexington, Kentucky residents.

Based on the information at the table below, what are the units used to measure the population for the different states?(How many zeroes you need to add?) State Population Death Row prisoners California 28 168 247 Florida 12 377 294 Illinois 11 544 120 Nevada 1 060 45

Thousands

An example of a quantitative variable is the

Time taken to complete a task.

A survey would be appropriate if you want to determine the average age of University of Kentucky students.

True

Inference is the act of drawing conclusions about something we can't know for sure based on info we have assumed to be accurate

True

Numbers of elliptical machines in every YMCA in KY is NOT qualitative (categorical) variable.

True

Shades of red paint in a home improvement store is qualitative (categorical) variable.

True

The correlation coefficient should only be used for a linear scatterplot.

True

Stat's library of literary classics includes issues of certain not-so-scholarly periodicals. The total number of issues of four such periodicals, together with the percentages of Dr. Stat's entire library that they comprise, are as follows: PeriodicalSpider ManSolder of FortuneWorld Wrestling Federation-WWFMadNumber1567826104% of Library31.2%15.6%8.7%20.8% One of the percentages in this table is incorrect. Which is it?

WWF

If we are testing the null hypothesis H0: p < or = 0.35 versus HA: p > 0.35 and we compute our test statistic (z-score) to be z = 2.5, then:

We Accept Ha and Reject Ho

Please read page 108 Beyond the numbers 2 and answer the next 3 questions using this information. Title: Americans Do Care About Climate ChangeAuthor: Annie LeonardSource: New York Times May 8, 2014. https://www.nytimes.com/roomfordebate/2014/05/08/climate-debate-isnt-so-heated-in-the-us/americans-do-care-about-climate-change . The following is an excerpt from the New York Times article: Americans do care about climate change. Polls showing lower levels of concern than in some countries don't tell the whole story. I travel widely around the U.S., attending meetings at schools, churches and community gatherings. Everywhere I go, I see people who are not only concerned about climate change, but are actively working on solutions.Nearly two-thirds (67%) of Americans accept the scientific evidence of global warming; fewer than one in six remain in denial. The full report referenced by Leonard's article tells us that the original survey was conducted by the Pew Research Center in October 2013. There was a (95%) margin of sampling error of about 2.9% associated with the entire sample. Question: What are the Pew Center poll's sample and statistic?

We don't know the size of the sample, but the implication is that it is a sample of Americans. The statistic reported is that 67% accept scientific evidence of global warming.

In general ,the phrase "95% confidence" means that

We got these results using a method that gives correct answers in 95% of all samples.

The following is from "A brief history of food coloring and its regulation" by Adam Burrows, Harvard Law School Class of 2006: "It was at this time that the FDA received word of Russian studies published in 1968 and 1970. The studies claimed that Red No. 2 caused rats to develop intestinal tumors and was toxic to the gonads and embryos. The studies were almost universally discredited, as the experiments were poorly designed and reported. Most significantly, there were serious questions as to whether the dye the Soviets tested was actually Red No. 2. But the news caught the attention of the public, and FDA officials scrambled to launch new tests to confirm the safety of the dye. After a series of tests examining the claims of gonad and embryonic toxicity, the FDA's Associate Commissioner for Science announced, 'The question concerning reproduction toxicity can probably be closed.' That left the cancer issue. The FDA conducted an experiment with 500 rats designed to put the issue to rest once and for all. Unfortunately, instead of being described as 'definitive', the study is referred to by FDA scientists as the 'botched' or 'bungled' experiment. Rats that were fed the dye were mixed up with the control group, and rats that died in their cages were left to rot, rendering them unfit for pathological examination. After trying to decipher the study, the FDA concluded that Red No. 2 had 'no apparent effect' on the rats. FDA Commissioner Alexander Schmidt was forced to defend this decision on CBS' Face the Nation." In the food coloring cancer experiment, what was most likely the response variable?

Whether or not the rats developed intestinal tumors

In the food coloring cancer experiment, what was most likely the explanatory variable?

Whether or not the rats were given Red No. 2.

Suppose someone said to you, "Sure, of the 1,042 surveyed by the poll, 90% agreed, but I bet if you interviewed all American adults, you could potentially find only 50% agreeing!" Is this a possible scenario and, if so, why?

Yes, it is possible. The 90% was just from a sample of American adults, not results from all American adults.

Social Media Sampling Suppose you have 113 Friends on Facebook and you want to choose a simple random sample of 20 of them. What is your population?

Your 113 Friends on Facebook

A newspaper reports "The percent decrease in the amount of wolves is 150%". What does this mean?

c) This is not possible. "percent decrease" can't be more than 100%

A Dean of Admissions at U.K. once tallied up the ACT scores for ALL entering freshman for that year and reported that the average was 25. A faculty member from Sociology demanded that the Dean attach a margin of error. This faculty member is:

confused, because the Dean's figure was not subject to any sampling variability

A Ph.D. candidate in the College of Education once defended her misleading and confusing questionnaire by arguing that her margin of error was low, only about 3%. This argument is:

confused, because the margin of error has nothing to do with biased questionnaire designs

Difficult Dilbert Dialogue The following dialogue is from a Dilbert cartoon published April 17, 1996.Secretary: Oh my! This is shocking!Boss: What?Secretary: 40% of all sick days taken by our staff are Fridays and Mondays!Boss: What kind of idiot do they think I am?Secretary: Not an idiot savant, they can do math. The secretary is trying to poke fun at her pointy-headed boss. Is she successful or is the joke on her?

i. Successful. Assuming an employee picks a single workday at random to be absent, the chances that the employee will pick a Monday or a Friday are 2/5 which is 40%

Let's put some other words into the secretary's dialogue. What if she had said the following?Secretary: When employees choose to take off a pair of sick days in a Tuesday-Monday period of time, 40% of the time they choose Friday and Monday as the two days they pick!The following two questions explore in what sense this is or is not a different situation than the one in the actual cartoon. Question: If we denote the five usual workdays as M,T,W,R, and F (using R for Thursday), which of the following lists all pairs of possible workdays.

iii. (M,T), (M,W), (M,R), (M,F), (T,W), (T,R), (T, F), (W,R), (W,F), (R,F)

What can one say about the sampling distribution of a sample statistic based on an SRS?

it is about bell-shaped and peaks above the parameter

74% of the 398 student who attended the October 15th lecture said they know how to "explain correctly a confidence statement". If these 398 were a simple random sample drawn from the entire UK student population, and the 95% confidence interval is 74%+/-5%, in which of these cases would the confidence interval be wider than the one calculated?

neither of the listed answers

A recent study has shown that 39% of a poll of 416 US parents say they get frustrated by technology because "it makes it hard to have conversation" with their children. The proportion of all US parents that get frustrated by technology is the

parameter

A recent study has shown that 39% of a poll of 416 US parents say they get frustrated by technology because "it makes it hard to have conversation" with their children. All US parents make up the

population

You want to know the opinions of American school teachers about establishing a national test for high school graduation. You obtain a list of the members of the National Education Association (the largest teachers' union) and mail a questionnaire to 2500 teachers chosen at random from this list, all of whom return the questionnaire. In all, 500 were in favor of establishing such a test. In this case the statistic is:

the 20%who were in favor of establishing the test

You want to know the opinions of American school teachers about establishing a national test for high school graduation. You obtain a list of the members of the National Education Association (the largest teachers' union) and mail a questionnaire to 2500 teachers chosen at random from this list, all of whom return the questionnaire. In all, 500 were in favor of establishing such a test. In this situation, the sample is:

the 2500 teachers to whom you mailed the questionnaire

Which changed the most, the mean or the median?

the mean changed the most

"Congress passed a ban on the sale of assault weapons. Now there is a move to repeal that ban. Do you agree that the ban on the sale of assault weapons should be repealed?" You ask that 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 95% confidence statements about the percent of all adults in both states who agree. Your margin of error for Indiana is

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

If a significance test gives a p-value of 0.99, then we can say that

we do not have good evidence against the null hypothesis

If we are testing the null hypothesis H0: p < or = 0.75 versus HA: p > 0.75 and we compute our standard score (z-score) to be z = 6.5, then:

we have "significant" results, with a p-value that is less than 0.05

"We are 90% confident that between 86% and 93% of all Americans dislike Tennessee volunteer orange." To increase the level of confidence to 95%, the length of the confidence interval would be

wider