In Exercises 29–32, identify the level of measurement of the data as nominal, ordinal, interval, or ratio. Also, explain what is wrong with the given calculation.

Social Security Numbers As part of a project in a statistics class, students report the last four digits of their Social Security numbers, and the average (mean) of those digits is computed to be 4.7.

Countable For each of the following, categorize the nature of the data using one of these three descriptions: (1) discrete because the number of possible values is finite; (2) discrete because the number of possible values is infinite but countable; (3) continuous because the number of possible values is infinite and not countable.

a. Exact lengths of the feet of members of the band the Monkees

Countable For each of the following, categorize the nature of the data using one of these three descriptions: (1) discrete because the number of possible values is finite; (2) discrete because the number of possible values is infinite but countable; (3) continuous because the number of possible values is infinite and not countable.

c. The number of albums sold by the Monkees band

Directions in Degrees Standard navigation systems used for aviation and boating are based on directions measured in degrees, with north represented by 0° Relative to north, east is 90°, south is 180°, and west is 270°. What is the level of measurement of such directions measured in degrees?

Discrete/Continuous Data Which of the following describe discrete data

c. The exact times that randomly selected students spend on smart phones during the preceding week

E-Cigarette Survey In a survey of 36,000 adults, 3.7% said that they regularly use E-cigarettes (based on data from the National Center for Health Statistics).

a. Identify the sample and population.

E-Cigarette Survey In a survey of 36,000 adults, 3.7% said that they regularly use E-cigarettes (based on data from the National Center for Health Statistics)

b. Is the value of 3.7% a statistic or parameter?

Reported Versus Measured In a survey of 1046 adults conducted by Bradley Corporation, subjects were asked how often they wash their hands when using a public restroom, and 70% of the respondents said “always.”

a) Identify the sample and the population.

Sampling Method The patients were recruited among those at a Veterans Affairs hospital. What type of sampling best describes the way in which the subjects were chosen: simple random sample, systematic sample, convenience sample, stratified sample, cluster sample? Does the method of sampling appear to adversely affect the quality of the results?

Exercises 5–8 refer to the study of an association between which ear is used for cell phone calls and whether the subject is left-handed or right-handed. The study is reported in “Hemispheric Dominance and Cell Phone Use,” by Seidman et al., JAMA Otolaryngology—Head & Neck Surgery, Vol. 139, No. 5. The study began with a survey e-mailed to 5000 people belonging to an otology online group, and 717 surveys were returned. (Otology relates to the ear and hearing.)

Experiment or Observational Study Is the study an experiment or an observational study? Explain.

Sampling Method Assume that the population consists of all students currently in your statistics class. Describe how to obtain a sample of six students so that the result is a sample of the given type.

a. Simple random sample

Sampling Method Assume that the population consists of all students currently in your statistics class. Describe how to obtain a sample of six students so that the result is a sample of the given type.

b. Systematic sample

Sampling Method Assume that the population consists of all students currently in your statistics class. Describe how to obtain a sample of six students so that the result is a sample of the given type.

c. Stratified sample

Sampling Method Assume that the population consists of all students currently in your statistics class. Describe how to obtain a sample of six students so that the result is a sample of the given type.

d. Cluster sample

Sampling Method Assume that the population consists of all students currently in your statistics class. Describe how to obtain a sample of six students so that the result is a sample of the given type.

e. Convenience sample

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

Cormorant Density Cormorant bird population densities were studied by using the “line transect method” with aircraft observers flying along the shoreline of Lake Huron and collecting sample data at intervals of every 20 km (based on data from Journal of Great Lakes Research).

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

Reported and Observed Results A Harris Interactive study involved 1013 adults who were interviewed about washing their hands in restrooms and another 6336 adults who were observed in public restrooms.

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

Criminology Researchers randomly selected 50 convicted felons from each category of burglary, auto theft, and assault.

In Exercises 29–32, indicate whether the observational study used is cross-sectional, retrospective, or prospective.

Heart Health Study Samples of subjects with and without heart disease were selected, and then researchers looked back in time to determine whether they took aspirin on a regular basis.

In Exercises 29–32, indicate whether the observational study used is cross-sectional, retrospective, or prospective.

Marijuana Study Researchers from the National Institutes of Health want to determine the current rates of marijuana consumption among adults living in states that have legalized the use of marijuana. They conduct a survey of 500 adults in those states.

In Exercises 33–36, identify which of these designs is most appropriate for the given experiment: completely randomized design, randomized block design, or matched pairs design.

Lunesta Lunesta is a drug designed to treat insomnia. In a clinical trial of Lunesta, amounts of sleep each night are measured before and after subjects have been treated with the drug.

In Exercises 33–36, identify which of these designs is most appropriate for the given experiment: completely randomized design, randomized block design, or matched pairs design.

West Nile Vaccine Currently, there is no approved vaccine for the prevention of infection by West Nile virus. A clinical trial of a possible vaccine is being planned to include subjects treated with the vaccine while other subjects are given a placebo.

Simple Random Sample vs. Random Sample Refer to the definition of simple random sample here and its accompanying definition of random sample enclosed within parentheses. Determine whether each of the following is a simple random sample and a random sample.

a. In Major League Baseball, there are 30 teams, each with an active roster of 25 players. The names of the teams are printed on 30 separate index cards, the cards are shuffled, and one card is drawn. The sample consists of the 25 players on the active roster of the selected team.

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

Highway Strength The New York State Department of Transportation evaluated the quality of the New York State Thruway by testing core samples collected at regular intervals of 1 mile.

In Exercises 21–28, determine whether the study is an experiment or an observational study, and then identify a major problem with the study.

Drinking and Driving A researcher for a consortium of insurance companies plans to test for the effects of drinking on driving ability by randomly selecting 1000 drivers and then randomly assigning them to two groups: One group of 500 will drive in New York City after no alcohol consumption, and the second group will drive in New York City after consuming three shots of Jim Beam bourbon whiskey.

In Exercises 21–28, determine whether the study is an experiment or an observational study, and then identify a major problem with the study.

Sleep Study When designing the study of a new treatment for insomnia in adults, researchers were criticized because their test subjects consisted of 75 college students. They then expanded the study so that 750 college students were given the treatment.

In Exercises 21–28, determine whether the study is an experiment or an observational study, and then identify a major problem with the study.

Atkins Weight Loss Program An independent researcher tested the effectiveness of the Atkins weight loss program by randomly selecting 1000 subjects using that program. Each of the subjects was called to report their weight before the diet and after the diet.

In Exercises 5–8, determine whether the given source has the potential to create a bias in a statistical study.

AAA The American Automobile Association (AAA) is a not-for-profit federation of motor clubs that provides automotive and travel services. AAA conducts a survey of its members about their use of public transportation versus private automobiles.