Test 1 Review

Ordinal

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ranks of scores in a tournament. Nominal Interval Ratio Ordinal

The frequency distribution refers to the a data set of 30 screw lengths. The screws had been labeled as having a length of 3-3/4 in. It begins with a lower class limit of 3.720 ​inches and uses a class width of 0.010 inches. If displayed in a Histogram format, the data would have a left tail, or would be "skewed to the left" or "negatively skewed".

What is the class width? Would a Histogram be normal (bell shaped) or described as another term? If so, please define.

Touch

The bars in a histogram __________.

TOUCH

The bars in a histogram​ __________.

Yes, it is approximately normal. The bars in a Histogram are always touching, and an (approximately) normal Histogram is bell-shaped.

The frequency distribution (above) represents frequencies of actual low temperatures recorded during the course of a​ 31-day month. Use the frequency distribution histogram to determine if the distribution is approximately​ normal?

​Yes, as the weight increases the highway mileage decreases.

A given data table lists weights​ (pounds) and highway mileage amounts​ (mpg) for seven automobiles, and has been formatted into a scatterplot (above). Is there a linear relationship between weight and highway​ mileage?

A. The magazine has an interest in the survey​ results, so the source of the survey is questionable.

A magazine ran a survey about a web site for downloading music. Readers could register their responses on the​ magazine's web site. Identify what is wrong. Choose the correct answer below: A. The magazine has an interest in the survey​ results, so the source of the survey is questionable. B. The sample is a voluntary response​ sample, so there is a good chance that the results do not reflect the population. C. The sample is a​ census, so there is a good chance that the results do not reflect the population. D. It is likely that the survey used a loaded​ question, so the results of the survey are not reliable.

A. The sample is a voluntary response​ sample, so there is a good chance that the results do not reflect the population.

A magazine ran a survey about a web site for downloading music. Readers could register their responses on the​ magazine's web site. Choose the correct answer below. A. The sample is a voluntary response​ sample, so there is a good chance that the results do not reflect the population. B. It is likely that the survey used a loaded​ question, so the results of the survey are not reliable. C. The magazine has an interest in the survey​ results, so the source of the survey is questionable. D. The sample is a​ census, so there is a good chance that the results do not reflect the population.

If foreign investment fell by 100%, it would be totally eliminated. It not possible for it to fall by more than 100 %.

A report about the decline of Western investment in third world countries included this: "After years of daily flights, several European airlines halted passenger service. Foreign investment fell 300 percent during the 1990s." What is wrong with this​ statement?

Systematic Sampling

A researcher selects every 732 th social security number and surveys the corresponding person. Which type of sampling did the researcher use?

The Pareto chart is more effective, it displays the information in decanting order.

A study was conducted to determine how people get jobs. The table below lists data from 400 randomly selected subjects. Compare the pie chart to the Pareto chart given on the left. Can you determine which graph is more effective in showing the relative importance of job​ sources?

relative frequency

A​ ________________ __________________ histogram has the same shape and horizontal scale as a​ histogram, but the vertical scale is marked with relative frequencies instead of actual frequencies.

scatterplot

A​ _____________________ is a plot of paired data​ (x,y) and is helpful in determining whether there is a relationship between the two variables.

B. The data are qualitative because they don't measure or count anything.

Determine whether the data described below are qualitative or quantitative and explain why. The types of food served by restaurants (Italian, Chinese, fast, etc.) Choose the correct answer below. A. The data are quantitative because they don't measure or count anything. B. The data are qualitative because they don't measure or count anything. C. The data are quantitative because they consist of counts or measurements. D. The data are qualitative because they consist of counts or measurements.

A. The data are qualitative because they don't measure or count anything.

Determine whether the data described below are qualitative or quantitative and explain why. The types of movies (drama, comedy, etc.) Choose the correct answer below. A. The data are qualitative because they don't measure or count anything. B. The data are quantitative because they consist of counts or measurements. C. The data are qualitative because they consist of counts or measurements. D. The data are quantitative because they don't measure or count anything.

The given description corresponds to an observational study.

Determine whether the given description corresponds to an observational study or an experiment. In a study of 413 women with a particular​ disease, the subjects were photographed daily.

The given value is a PARAMETER for the month because the data collected represent a POPULATION.

Determine whether the given value is a statistic or a parameter. A homeowner measured the voltage supplied to his home on all 30 days of a given month, and the average​ (mean) value is 113.3 volts.

The given value is a parameter for the month because the data collected represent a population.

Determine whether the given value is a statistic or a parameter. A homeowner measured the voltage supplied to his home on all 30 days of a given month, and the average​ (mean) value is 139.8 volts.

Parameter because the value is a numerical measurement describing a characteristic of a sample.

Determine whether the given value is a statistic or a parameter. A sample of seniors is selected and it is found that 25% own a computer.

The value is a PARAMETER because the value is a numerical measurement describing a characteristic of a POPULATION (refers to "all").

Determine whether the given value is a statistic or a parameter. In a study of all 3473 professors at a college, it found that 50 % own a television.

The ordinal level of measurement is most appropriate because the data can be ordered, but differences cannot be found or are meaningless.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Explain why. Ratings of hotels on a scale from 0 stars to 4 starsRatings of hotels on a scale from 0 stars to 4 stars.

D. The interval level of measurement is most appropriate because the data can be ordered, differences can be found and are meaningful, and there is no natural starting point.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Please explain why. Body temperature in degrees Fahrenheit. Choose the correct answer below. A. The ordinal level of measurement is most appropriate because the data can be ordered, but differences (obtained by subtraction) cannot be found or are meaningless. B. The ratio level of measurement is most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is a natural starting point C. The nominal level of measurement is most appropriate because the data cannot be ordered. D. The interval level of measurement is most appropriate because the data can be ordered, differences can be found and are meaningful, and there is no natural starting point.

RATIO

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ages of Children: 4, 5, 6, 7 and 8

Interval

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Monthly temperatures: 65° F, 70° F, 75° F, 80° F, and 85° F Choose the correct answer below: Ratio Nominal Interval Ordinal

Yes, it appears that births occur on the days of the week with frequencies that are about the same.

Does it appear that births occur on the days of the week with equal​ frequency in the cumulative frequency (above)? Let the frequencies be substantially different if any frequency is at least twice any other frequency.

The distribution appears to be skewed to the left ​(or negatively ​skewed).

Does the graph suggest that the distribution is​ skewed? If​ so, how?

The histogram has a longer right tail, so the distribution of the data is skewed to the right.

Does the histogram appear to be​ skewed?

No comma because the frequencies are roughly equal across the voltage classes.

Does the result appear to have a normal​ distribution? Why or why​ not?

Class Width: 6 Class Midpoints: 6.95, 12.95, 18.95, 24.95, 30.95 Class Boundaries: 3.95, 9.95, 15.95, 21.95, 27.95, 33.95

Identify the class​ width, class​ midpoints, and class boundaries for the given frequency distribution (above).

Lower Class Limits: 25, 30, 35, 40, 45, 50, 55 Upper Class Limits: 29,34, 39, 44, 49, 54, 59 Class Width: 5 Class Midpoints: 27, 32, 37, 42, 47, 52, 57 Class Boundaries: 24.5, 29.5, 34.5, 39.5, 44.5, 49.5, 54.5, 59.5 Number of individuals included in the summary: 93

Identify the lower class​ limits, upper class​ limits, class​ width, class​ midpoints, and class boundaries for the given frequency distribution (above). Also identify the number of individuals included in the summary.

Systematic Sampling

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. A researcher selects every 762th social security number and surveys the corresponding person. What type of sampling did the researcher use? Random Convenience Systematic Stratified Cluster

It is questionable that the sponsor is a candy company because this sponsor can be greatly affected by the conclusion.

Identify what is wrong: Several studies showed that after eating chocolate​, subjects had increased blood levels of antioxidants. Antioxidants have been associated with decreased risk of heart disease. A candy company financed this research.

Cluster

Identify which type of sampling is​ used: random, systematic, convenience,​ stratified, or cluster. To determine customer opinion of their check-in service​, American Airlines randomly selects 3030 flights during a certain week and surveys all passengers on the flight.

Cluster

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their check-in service, American Airlines randomly selects 60 flights during a certain week and surveys all passengers on the flights. Which type of sampling is​ used? Cluster Stratified Systematic Random Convenience

​No, a graph cannot help to overcome the deficiency. If the sample is a bad​ sample, there are no graphs or other techniques that can be used to salvage the data.

If we have a large voluntary response sample consisting of weights of subjects who chose to respond to a survey posted on the​ Internet, can a graph help to overcome the deficiency of having a voluntary response​ sample?

C. ​No, a graph cannot help to overcome the deficiency. If the sample is a bad​ sample, there are no graphs or other techniques that can be used to salvage the data.

If we have a large voluntary response sample consisting of weights of subjects who chose to respond to a survey posted on the​ Internet, can a graph help to overcome the deficiency of having a voluntary response​ sample? Choose the correct answer below. A. No, a graph cannot help to overcome the deficiency. Before​ graphing, all inaccurate values and outliers must be removed from the data set. B. ​Yes, a graph can help to overcome the deficiency. Certain graphs that hide any specific values in the​ data, such as pie​ charts, can be used to hide deficiencies in the sampling technique. C. ​No, a graph cannot help to overcome the deficiency. If the sample is a bad​ sample, there are no graphs or other techniques that can be used to salvage the data. D. ​Yes, a graph can help to overcome the deficiency. Any graph that is given with a sufficiently accurate description of any deficiencies in the sampling technique is no longer considered biased.

Random Sampling

In a poll conducted by a certain research​ center, 1175 adults were called after their telephone numbers were randomly generated by a​ computer, and 34% were able to correctly identify the president. Which type of sampling did the research center​ use? Cluster sampling Stratified sampling Convenience sampling Systematic sampling Random sampling

Random Sampling

In a poll conducted by a certain research​ center, 1288 adults were called after their telephone numbers were randomly generated by a​ computer, and 36% were able to correctly identify the secretary of state. Which type of sampling did the research center use? Random Cluster Stratified Systematic Convenience

A. The given description corresponds to an experiment.

In a study of 442 children with a particular​ disease, the subjects were given certain drugs to determine if the drugs have an effect on the disease. Does the given description correspond to an observational study or an​ experiment? A. The given description corresponds to an experiment. B. The given description corresponds to an observational study. C. The given description does not provide enough information to answer this question.

Yes, misconduct appears to be a major factor because the majority of retractions were due to misconduct.

In a study of retractions in biomedical​ journals: 405 were due to​ error, 194 were due to​ plagiarism, 888 were due to​ fraud, 291 were due to duplications of​ publications, and 273 had other causes. Does the Pareto chart (above) showing such retractions, appear to show misconduct​ (fraud, duplication,​ plagiarism) as a major​ factor? Please explain.

a nonzero axis

In a​ graph, if one or both axes begin at some value other than​ zero, the differences are exaggerated. This bad graphing method is known as​ __ ______________ ________.

No. The data values in each class could take on any value between the class​ limits, inclusive.

Is it possible to identify the exact values of all of the original service​ times?

Yes. The frequencies start low, reach a maximum, then become low again, and are roughly symmetric about the maximum frequency. The Histogram would be bell-shaped, and NOT skewed.

Refer to the frequency distribution (above) of 25 home voltage measurements below, with a lower class limit of 127.7 volts, and a class width of 0.2 volt. Does the result appear to have a normal​ distribution? Why or why​ not?

No. The data values in each class could take on any value between the class​ limits, inclusive.

Refer to the table summarizing service times​ (seconds) of dinners at a fast food restaurant. How many individuals are included in the​ summary? Is it possible to identify the exact values of all of the original service​ times?

B. It is questionable that the sponsor is a fitness equipment company because this sponsor can be greatly affected by the conclusion.

Several studies showed that after regular exercise on a treadmillafter regular exercise on a treadmill​, subjects had loweredlowered blood pressure. High blood pressure has been associated with increased risk of heartblood pressure. High blood pressure has been associated with increased risk of heart disease and stroke.disease and stroke. A fitness equipment companyfitness equipment company financed this research. Choose the correct answer below. A. It is not possible to take accurate measurements. B. It is questionable that the sponsor is a fitness equipment company because this sponsor can be greatly affected by the conclusion. C. The data used in the studies is not reliable because it was not measured by the administrator. D. Since the research is composed of voluntary response​ samples, there may be key data points missing.

The data are continuous because the data can take on any value in an interval.

State whether the data described below are discrete or​ continuous, and explain why. The exact ages in hours of different cockroaches found in a certain city.

The data are continuous because the data can take on any value in an interval (no set distance between chairs).

State whether the data described below are discrete or​ continuous, and explain why. The exact distances (in centimeters) between the chairs in a college classroom.

The data are discrete because the data can only take on specific values.

State whether the data described below are discrete or​ continuous, and explain why. The numbers of children in families.

The data are discrete because the data can only take on specific values.

State whether the data described below are discrete or​ continuous, and explain why. The numbers of employees working at different companies.

The (frequency) distribution appears to be SKEWED TO THE RIGHT ​(or positively ​skewed).

The given data represent the number of people from a​ town, aged​ 25-64, who subscribe to a certain print magazine. The frequency polygon graph (above) suggests the distribution is ____________ ____ ______ __________?

​No, there does not appear to be a correlation because there is no general pattern to the data.

The heights of a certain​ country's presidents and their main opponents in the election campaign have been constructed into a scatterplot (above). Does there appear to be a​ correlation?

The histogram has a LONGER RIGHT TAIL, so the distribution of the data is SKEWED TO THE RIGHT.

The histogram has a ____________ __________ ________, so the distribution of the data is ____________ ____ ______ __________.

The histogram represents 17 debate team members.

The histogram (above) represents the weights​ (in pounds) of members of a certain​ high-school debate team. How many team members are included in the​ histogram (above)?

The histogram represents 27 debate team members.

The histogram below represents the weights​ (in pounds) of members of a certain​ high-school debatedebate team. How many team members are included in the​ histogram?

Ordinal

The level of measurement of: Positions of runners in a race is ______________. Interval Ordinal Ratio Nominal

With a data set that is so​ small, the true nature of the distribution cannot be seen with a histogram.

The population of ages at inauguration of all U.S. Presidents who had professions in the military is​ 62, 46,​ 68, 64, 57. Why does it not make sense to construct a histogram for this data​ set?

B. With a data set that is so​ small, the true nature of the distribution cannot be seen with a histogram.

The population of ages at inauguration of all U.S. Presidents who had professions in the military is​ 62, 46,​ 68, 64, 57. Why does it not make sense to construct a histogram for this data​ set? Choose the correct answer below. A. Adequate class boundaries for a histogram cannot be found with this data set. B. With a data set that is so​ small, the true nature of the distribution cannot be seen with a histogram. C. There must be an even number of data values in the data set to create a histogram. D. This data set would yield a histogram that is not​ bell-shaped.

The lengths of the rows are similar to the heights of bars in a​ histogram; longer rows of data correspond to higher frequencies. Generally, stem-and-leaf plot(s) are a (visual) 90 degree rotation, representative of a histogram (lengths being equal to heights).

The stem-and-leaf plot (above) shows the test scores 67, 73, 85, 75, 89, 89, 88, 90, 98, 100. How does the​ stem-and-leaf plot show the distribution of these​ data?

The distribution appears to be skewed to the right ​(or positively ​skewed).

The the frequency polygon (above), represents data from the frequency distribution of the number of people from a​ town aged​ 25-64, who subscribe to a certain print magazine. Does the graph (above) suggest that the distribution is​ skewed? If​ so, how?

Stratified

To determine her air quality​, Samantha divides up her day into three​ parts: morning,​ afternoon, and evening. She then measures her air quality at 33 randomly selected times during each part of the day. What type of sampling is used? Stratified Random Convenience Systematic Cluster

Stratified

To determine her heart rate​, a subject divides their day into three​ parts: morning,​ afternoon, and evening. They then measure their heart rate at 22 randomly selected times during each part of the day. What type of sampling was used? Random Stratified Cluster Convenience Systematic

C. If the device eliminated all bike thefts, it would reduce odds of bike theft by 100%, so the 300% figure is misleading.

What is wrong with this​ statement: An ad for a device used to discourage bike thefts stated: "This device reduces your odds of bike theft by 300 percent." Choose the correct answer below. A. If bike theftsbike thefts fell by​ 100%, it would be cut in half.​ Thus, a decrease of​ 200% means that it would be totally​ eliminated, and a decrease of more than​ 200% is impossible. B. The actual amount of the decrease in bike thefts is less than​ 100%. C. If the device eliminated all bike thefts, it would reduce odds of bike theft by 100%, so the 300% figure is misleading. D. The statement does not mention the initial amount of bike thefts.

Quantitative

Which of the following is NOT a level of​ measurement? Ordinal Nominal Ratio Quantitative

Quantitative

Which of the following is NOT a level of​ measurement? Quantitative Nominal Ordinal Ratio

C. Utilizing valid statistical methods and correct sampling techniques

Which of the following is NOT a misuse of​ statistics? A. Concluding that a variable causes another variable because they have some correlation B. Misleading graphs C. Utilizing valid statistical methods and correct sampling techniques D. Making conclusions about a population based on a voluntary response sample

D. Utilizing valid statistical methods and correct sampling techniques

Which of the following is NOT a misuse of​ statistics? A. Misleading graphs B. Making conclusions about a population based on a voluntary response sample C. Concluding that a variable causes another variable because they have some correlation D. Utilizing valid statistical methods and correct sampling techniques

B. Quiz scores from a college level statistics course are analyzed to determine student progress.a Not voluntary (and no bias).

Which of the following is NOT a voluntary response​ sample? A. A radio station asks for​ call-in responses to a question concerning city recycling. B. Quiz scores from a college level statistics course are analyzed to determine student progress. C. A local dentist asks her patients to fill out a questionnaire and mail it back to determine the quality of the care received during an office visit. D. A survey is taken at a mall by asking passersby if they will fill out the survey.

A. Quiz scores from a college level statistics course are analyzed to determine student progress.

Which of the following is NOT a voluntary response​ sample? A. Quiz scores from a college level statistics course are analyzed to determine student progress. B. A radio station asks for​ call-in responses to a question concerning city recycling. C. A survey is taken at a mall by asking passersby if they will fill out the survey. D. A local dentist asks her patients to fill out a questionnaire and mail it back to determine the quality of the care received during an office visit.

Frequency Polygon

​A(n) __________________ ______________ uses line segments to connect points located directly above class midpoint values.

frequency polygon

​A(n) __________________ ______________ uses line segments to connect points located directly above class midpoint values.