Unit I-1 Multiple-Choice Review
For multiple choice questions place the best answer in the blank. For the remainder of the test, show all work and answers on this paper. Remember that your explanations are important as well as your answers. Communication is as important as correct answers.
______1. In one study on the effect of niacin on cholesterol level, 100 subjects who
acknowledged being long-time niacin takers, had their cholesterol levels
compared with those of 100 people who had never taken niacin. In a second study,
50 subjects were randomly chosen to receive niacin and 50 were chosen to receive a placebo.
A. The first study was a controlled experiment, while the second was an
observational study.
B. The first study was an observational study, while the second was a
controlled experiment.
C. Both studies were controlled experiments.
D. Both studies were observational studies.
E. Each study was part controlled experiment and part observational study.
______2. A pharmacist wants to study the effect of temperature on the potency of a headache pain reliever when it is stored for extended periods of time. Thirty pills were randomly assigned to each of the temperatures for a specified storage time. The time it took to gain relief from a headache was measured for each pill. Which of the following is the correct description of the treatment, experimental unit, and the response, respectively?
A. Specific temperature, pill, relief time
B. Specific temperature, the pharmacist, relief time
C. Pill, relief time, specific temperature
D. Random assignment, pill, relief time
E. Specific temperature, relief time, pill
______3. Students in AP Statistics want to determine the percentage of Greenhill students who live in the city of Dallas. There are 1248 students in the school. Given a list of all the Legacy Groups in the school, the students randomly select one student from each group to be part of the survey. This sampling method can be described as
A. A systematic sample
B. A simple random sample
C. A cluster sample
D. A stratified random sample
E. An observational sample study
______4. We want to draw a sample of 5 drivers from a population of 50 drivers who have been convicted of speeding. If the drivers are labeled 01, 02, 03, …, 50 and the following line is used from a random number table.
22368 46573 25595 85393 30995 89198 27982 53401 93965 34095 52666
Which of the following represents the sample of 5 drivers, starting from the left?
A. 22, 36, 8, 46, 32
B. 22, 46, 25, 30, 27
C. 22, 36, 25, 30, 27
D. 22, 36, 46, 32, 39
E. 22, 23, 36, 46, 32
______5. A politician is considering running for public office. She wants to measure her name recognition by doing a survey in her district. Which of the following survey methods would produce unbiased results?
A. The politician stands in front of a grocery store in her district on Saturday morning and asking each person entering the store if he or she recognizes her name.
B. Place pollsters in front of every grocery store in her district on Saturday morning and asking each person entering the store if he or she recognizes the politician’s name.
C. Sending a survey card to all registered voters in her district asking them to call a number to state whether or not they recognize the politician’s name.
D. Calling people from her district listed in the phone book and asking each if he or she recognizes the politician’s name.
E. Gather a random sample of eligible voters in her district, visit their homes, and ask each if he or she recognizes the politician’s name.
______6. For which of the following purposes would it be most unreasonable to use a census?
A. To determine the mean selling price of houses in your neighborhood.
B. To determine the proportion of red snappers with a high mercury level in the Gulf of Mexico.
C. To determine the difference between the proportion of engineering professors and the proportion of business professors in favor of a new teaching initiative at a large university.
D. To determine the mean wage earned by construction workers in a small town.
E. To determine the proportion of students with a learning disability in a small rural high school.
______7. A teacher believes that giving his students a practice quiz every week will motivate them to study harder, leading to an overall understanding of the course material. He tries this technique for a year, and everyone in the class achieves a grade of at least C. Is this an experiment or a study?
A. An experiment, but with no reasonable conclusion possible about cause and effect.
B. An experiment, thus making cause and effect a reasonable conclusion.
C. An observational study, because there was no use of a control group.
D. An observational study, but a poorly designed one because randomization was not used.
E. An observational study, and thus a reasonable conclusion of association but no of cause and effect.
______8. A major automobile manufacturer is trying to improve customer service at its dealerships across the United States. 200 randomly selected customers in Arizona who recently purchased a vehicle from this manufacturer were asked if they were satisfied with the customer service at the dealership. Is it reasonable to generalize the results of this survey to the population of all customers in the U. S. who had purchased a vehicle from this manufacturer?
A. No, because only one sample was taken.
B. No, because customers were only sampled from one state.
C. No, because 200 is not a very large sample.
D. Yes, because a random sample was taken.
E. Yes, because the manufacturer sells these vehicles all over the U. S.
______9. In a clinical trial, 30 sickle-cell patients are randomly assigned to two groups. One group is then randomly assigned the currently marketed medicine, and the other group receives the experimental medicine. Each week patients report to the clinic where blood tests are conducted. The lab technician is unaware of the kind of medicine the patient is taking and the patient is also unaware which medicine he/she has been given. This design can be described as
A. A completely randomized design, with the currently marketed medicine and the experimental medicine as the two treatments.
B. A matched-pairs design, with the currently marketed medicine and the experimental medicine forming a pair
C. A randomized block design, with the currently marketed medicine and the experimental medicine as the two blocks.
D. A randomized block design, with the currently marketed medicine and the experimental medicine as the two treatments
E. A randomized block design, in which blinding occurs.
______10. In a clinic, 50 patients with sleep disorders are randomly assigned to one of two different groups. Patients in one group are given medication before bedtime. Patients in the other group are given blindfolds and soft music is played at bedtime. Each patient is attached to a machine that records breathing patterns. From the patterns, it is possible to determine if the patient is awake or asleep. The data will be used to decide which method is more effective in helping patients with sleep disorders. Which of the following statements is correct in the context of this experiment?
A. This is a single blind experiment, since only one group uses blindfolds
B. This is a single blind experiment, because only patients and not doctors use blindfolds
C. This is a double-blind experiment since patients are blindfolded and the doctor does not know which patient receives which treatment
D. This experiment cannot be a single blind experiment, because many patients do not like being blindfolded
E. This experiment cannot be a double blinded, because patients will know which treatment they are receiving, although the examining doctor will not.
______11. A study of existing records of 27,000 automobile accidents involving children in Michigan found that about 10 percent of children who were wearing a seatbelt (group SB) were injured and that about 15 percent of children who were not wearing a seatbelt (group NSB) were injured. Which of the following statements should NOT be included in a summary report about this study?
A Driver behavior may be a potential confounding variable.
B. The child’s location in the car may be a potential confounding variable.
C. This study was not an experiment, and cause-and-effect inferences are not warranted.
D. This study demonstrates clearly that seat belts save children from injury.
E. Concluding that seatbelts save children from injury is risky, at least until the study is independently replicated.
______12. The makers of Save-More Showerheads claim that their showerhead will save water and therefore save money on water bills. They cite evidence from a recent study where sales records from a home improvement center were used to identify customers who had purchased a Save-More Showerhead. Twenty of the customers were contacted and 19 indicated that they used less water in the month following the installation of the showerhead. Which of the following statements best describes the claim made by the makers of the showerheads?
A) It is valid. The evidence shows lower water use by nearly all of the customers.
B) It is invalid because not enough customers were included in the survey.
C) It is invalid because changes in water usage due to the showerhead are confounded with other variables.
D) It is invalid because Save-More should have sold more than one type of showerhead.
E) It is invalid because no other brands of showerheads were include din the study.
______13. A large telecommunications company wants to improve employee productivity. Studies have shown that exercise could help. The company decides to offer two different types of programs during the workday. One program is an aerobics class for 30 minutes; the other is a weight room session for 30 minutes. Employees can choose the program in which they want to participate. If the company truly wants to find out if exercise during the day improves worker productivity, what else is needed in the study?
I. A third type of exercise, as more treatments will yield more reliable information.
II. A control group that does not exercise in order to determine if an increase in productivity was actually due to one of the treatments.
III. Random assignment of employees to treatment groups, instead of allowing employees to choose.
A) I only
B) II only
C) III only
D) I and III only
E) II and III only
______14. A radio station is interested in predicting the proportion of registered voters who support an increase in the state sales tax to construct additional regional parks across the state. Listeners of the station’s programs were asked to go to the station’s web site and indicate whether they favored or opposed such an increase. 1744 listeners logged on and 922 (53%) were against the increase. Which one of the following is NOT a correct statement about possible bias in the sampling procedure?
A) Only people with Internet access would be counted.
B) 1744 is quite a large sample so any bias that might have occurred can be overcome.
C) Only people listening to the station would be counted.
D) Those who responded may not even be registered voters.
E) It is likely that only those who feel passionately about the proposal would respond.
Unit I-1 Multiple Choice Review Solutions
1. B
2. A
3. D
4. C
5. E
6. B
7. A
8. B
9. A
10. E
11. D
12. C
13. E
14. B