A 1992 Roper poll found that 22% of Americans say that the Holocaust may not have happened. The actual question asked in the poll was "Does it seem possible or impossible to you that the Nazi extermination of the Jews never happened? "and 22% responded "P
the question is worded in a confusing manner.
A political party sends a mail survey to 1500 randomly selected registered voters in a community. The survey asks respondents to give an opinion about the job performance of the current President. Of the 1500 surveys sent out, 480 are returned, and of the
the 480 surveys returned.
A political party sends a mail survey to 1500 randomly selected registered voters in a community. The survey asks respondents to give an opinion about the job performance of the current President. Of the 1500 surveys sent out, 480 are returned, and of the
a survey containing nonresponse.
A researcher studying the effect of price cuts on consumers' expectations makes up two different histories of the store price of a hypothetical brand of laundry detergent for the past year. Eight students in a class view one or the other price history on
a randomized comparative experiment.
In order to investigate treatments for morbid obesity, obese subjects satisfying fairly strict requirements were randomly assigned to one of three groups: gastric bypass surgery; participation in a diet and exercise program; or both gastric bypass surgery
randomization.
A researcher studying the effect of price cuts on consumers' expectations makes up two different histories of the store price of a hypothetical brand of laundry detergent for the past year. Eight students in a class view one or the other price history on
the price they would expect to pay.
A researcher finds 2000 mildly overweight women who exercise regularly, have not had a heart attack, and are willing to participate in the study. She randomly assigns 500 of the women to take an appetite suppressant. The other 500 women are given a placeb
the treatment taken by women in the study � appetite suppressant or placebo.
The law of large numbers states that as the number of observations drawn at random from a population with finite mean ? increases, the mean of the observed values
tends to get closer and closer to the population mean ?.
I flip a coin twice and count the number of heads. Which of the following is a valid assignment of probabilities for the number of heads observed in two flips?
All of the above.
In a survey of sleeping habits, 8400 national adults were selected randomly and contacted by telephone. Respondents were asked, "Typically, how many times per week do you sleep less than 6 hours during the night?" On average, those surveyed reported an av
1.8 is a statistic and represents an estimate of the unknown value of a parameter of interest.
Suppose you're in a class of 35 students. The instructor takes a simple random sample of 7 students and observes their heights. Imagine all of the different samples possible. Let X denote the tallest height in your sample. The distribution of all values t
the sampling distribution of X.
Suppose you interview 10 randomly selected workers and ask how many miles they commute to work. You'll compute the sample mean commute distance. Now imagine repeating the survey many, many times, each time recording a different sample mean commute distanc
the sampling distribution of the sample mean.
The central limit theorem says that when a simple sample of size n is drawn from any population with mean ? and standard deviation ?, then when n is sufficiently large
the distribution of the sample mean is approximately Normal.
Nationwide, the amount charged by doctors for performing a particular minor surgical procedure averages $1220 and varies with a standard deviation of $300. We randomly select 160 bills from the population of all bills charged for this surgery. Let x repre
mean = $1220 and standard deviation = $23.72.
A manufacturing process produces bags of cookies. The distribution of content weights of these bags is Normal with mean 16.0 oz and standard deviation 0.8 oz. We will randomly select n bags of cookies and weigh the contents of each bag selected. How many
64 bags
To assess the opinion of students at the Ohio State University about campus safety, a reporter for the student newspaper interviews 15 students she meets walking on the campus late at night who are willing to give their opinion. The sample is
the 15 students interviewed.
A small math department has 6 faculty members and 30 students. It can send 6 people to a national convention and they would like to send 4 students and 2 faculty members. Of the 30 students, 4 are selected randomly, and then 2 faculty members are randomly
stratified random sampling.
A stratified random sample corresponds to which of the following experimental designs?
a block design
A researcher conducts a study to investigate the effect of nicotine and alcohol on blood pressure. The factors in this study are
nicotine and alcohol.
A researcher finds 2000 mildly overweight women who exercise regularly, have not had a heart attack, and are willing to participate in the study. She randomly assigns 500 of the women to take an appetite suppressant. The other 500 women are given a placeb
the amount of weight lost.
In order to investigate treatments for morbid obesity, obese subjects satisfying fairly strict requirements were randomly assigned to one of three groups: gastric bypass surgery; participation in a diet and exercise program; or both gastric bypass surgery
three treatments.
The law of large numbers states that as the number of observations drawn at random from a population with finite mean ? increases, the mean x of the observed values
tends to get closer and closer to the population mean ?.
The sampling distribution of a statistic is
the distribution of values taken by a statistic in all possible samples of the same size from the same population.
Suppose you interview 10 randomly selected workers and ask how many miles they commute to work. You'll compute the sample mean commute distance. Now imagine repeating the survey many, many times, each time recording a different sample mean commute distanc
the sampling distribution of the sample mean.
Parts being manufactured at a plant are supposed to weigh 40 grams. Suppose the distribution of weights has a Normal distribution with mean 40 grams and standard deviation 2 grams. Quality control inspectors randomly select 16 parts, weigh each, and then
is exactly Normal with mean 40 grams and standard deviation 0.5 grams.
To assess the opinion of students at the Ohio State University about campus safety, a reporter for the student newspaper interviews 15 students she meets walking on the campus late at night who are willing to give their opinion. The sample obtained is
probably biased.
A news release for a diet products company reports: "There's good news for the 65 million Americans currently on a diet." Its own study showed that people who lose weight can keep it off. The sample was 20 graduates of the company's program who endorsed t
biased, overstating the effectiveness of the diet.
The Excite Poll is an online poll at poll.excite.com. You click on an answer to become part of the sample. One poll question was "Do you prefer watching first-run movies at a movie theater, or waiting until they are available on home video or pay-per-view
the poll uses voluntary response, so the results tell us little about the population of all adults.
Researchers have noted that children that learn to play a musical instrument through taking lessons have higher average SAT scores, higher average GPA and higher average class rank. This is an example of
an observational study.
Which of the following are principles of experimental design?
All of the above
At a local health club, a researcher samples 75 people whose primary exercise is cardiovascular and 75 people whose primary exercise is strength training. The researcher's objective is to assess the effect of type of exercise on cholesterol. Each subject
an observational study.
Researchers have noted that children that learn to play a musical instrument through taking lessons have higher average SAT scores, higher average GPA and higher average class rank. The various measures of academic success described are examples of
response variables.
The law of large numbers states that as the number of observations drawn at random from a population with finite mean ? increases, the mean of the observed values
tends to get closer and closer to the population mean ?.
Nationwide, the amount charged by doctors for performing a particular minor surgical procedure averages $1220 and varies with a standard deviation of $300. We randomly select 160 bills from the population of all bills charged for this surgery. Let represe
mean = $1220 and standard deviation = $23.72.
A call-in poll conducted by a local radio station concluded that race would not be an issue in the 2008 presidential election. This conclusion was based on data collected from 450 calls made by local listeners. The sampling technique being used is
volunteer sampling
Some researchers have noted that adolescents who spend a lot of time playing video or computer games are at greater risk for depression and for violence. This is an example of
an observational study with lurking variables that may explain the association.
To investigate whether women are more likely than men to prefer Democratic candidates, a political scientist selects a large sample of registered voters, both men and women. She asks every voter whether they voted for the Republican or the Democratic cand
an observational study.
Which of the following data summaries are changed by adding a constant to each data value?
the mean
the median
the standard deviation
I and II
In a Normal model, about 68% of the data fall within 2 standard deviations of the mean.
False
Environmental researchers have collected data on rain acidity for years. Suppose that a Normal model describes the acidity (pH) of rainwater, and that water tested after last week's storm had a z-score of 1.8. This means that the acidity of that rain . .
had a pH 1.8 standard deviations higher than that of average rainwater.
Attendance at a university's basketball games follows a normal distribution with mean ? = 8,000 and standard deviation ? = 1,000. Estimate the percentage of games that have between 7,000 to 9,000 people in attendance.
The mean is greater than the median.
Which one of the following is a FALSE statement about the standard normal distribution?
The mean is greater than the median.
Which one of the following is a FALSE statement about density curves?
Total area under the curve depends on the shape of the curve.