1. 1. A nutritionist wants to study the effect of storage time (6, 12, and 18 months) on the amount of vitamin C present in freeze dried fruit when stored for these lengths of time. Vitamin C is measured in milligrams per 100 milligrams of fruit. Six fruit packs were randomly assigned to each of the three storage times. The treatment (Trt), experimental unit (EU), and response variable (RespVar) are respectively:
Trt: a specific storage time; EU: amount of vitamin C; RespVar: a fruit pack
B) Trt: a fruit pack; EU: amount of vitamin C; RespVar: a specific storage time
C) Trt: random assignment; EU: a fruit pack; RespVar: amount of vitamin C
E) Trt: a specific storage time; EU: the nutritionist; RespVar: amount of vitamin C
D) Trt: a specific storage time; EU: a fruit pack; RespVar: amount of vitamin C

2. 2) Forty male high school students and 40 female high school students with test anxiety were subjects in an experiment to determine the effectiveness of a new drug in lowering test anxiety. Forty of the students were chosen at random to receive the new drug. The remaining 40 received a placebo. The change in test anxiety was measured for each subject. The design of this experiment is
completely randomized with one factor, drug.
b) completely randomized with one factor, gender.
c) randomized block, blocked by drug and gender.
d) randomized block, blocked by drug.
e) randomized block, blocked by gender.

3. 3. The primary reason for using blocking when designing an experiment is to reduce
the sensitivity of the experiment.
placebo effects.
c) the need for randomization.
d) bias.
e) variation.

4. 4. There are 15 classrooms in the building to sample from 4th period, each class has exactly 24 students. A sample of 30 students is chosen by the following procedure. Each of the 15 teachers selects 2 students from his/her classroom to be in the sample by numbering all the students from 1 to 24, then using the TI-83+ to select two different numbers between 01 and 24. The 2 students with those numbers are in the sample. What type of sampling method is this?
SRS
c) systematic d) convenience e) cluster
b) stratified

5. 5) According to a recent Gallup poll, about 60% of all Americans
adults owned a cell phone at the time of the poll. The results are
based on telephone interviews with a randomly selected national
sample of 998 adults, 18 years and older, conducted March 30-
April 2, What was the population of interest in this Gallup
poll?
all Americans adults.
B) all American adults who own cell phones.
C) The 998 adults who participated in the survey.
D) The participants in the survey who owned cell phones.
E) The population of interest cannot be determined by the information provided.

6. 6) When drawing five cards randomly from a deck, which is more likely, a royal flush or a full house? A royal flush is the five highest cards of a single suit. A full house is three of one denomination and two of another. How could you simulate 5-card hands? Once you have picked one card, you cannot pick that same card again. Describe how you will simulate a trial.
A) A trial is a single card. Use random numbers, ignoring repeated cards.
B) A trial is a single five-card hand. Use one set of random numbers, ignoring repeated cards.
C) A trial is a single five-card hand. Use five sets of random numbers.
D) A trial is a single five-card hand. Use five sets of random numbers, ignoring repeated cards.
E) A trial is five-card hands, dealt until the deck is completely dealt. Use five sets of random numbers, ignoring repeated cards.

7. C) Voluntary response bias D) Response bias
7) A newspaper reporter decided to sample residents of all major metropolitan areas in the entire country. This sampling asked if the residents liked living in their city, or are they considering moving, and if so, where? Unfortunately, this survey went over budget and was stopped, and only the east coast of the country was adequately interviewed. With regards to having this survey labeled as representing the entire country, what, if any, will be the most noticeable bias for this survey as it is now?
Nonresponse bias
C) Voluntary response bias
D) Response bias
B) Undercoverage of the population

8. 8. Which of the following are true about the design of matched-pair experiments?
Each subject might receive both treatments.
II. Each pair of subjects receives the identical treatment, and differences in their responses are noted.
III. Matched Pair is a type of blocking.
I only B. II only C. III only
E. II and III
D. I and III

9. 9. What is the best way to describe the design of this experiment?
Researchers would like to compare meditation and exercise to see which is more effective for reducing stress. One hundred people who suffer from high stress volunteer to participate in a study for ten weeks. Participants will either be given a 10-week course in meditation or will participate in a 10-week exercise program. The volunteers are randomly assigned to the two programs.
9. What is the best way to describe the design of this experiment?
a) completely randomized
b) Blocked, by stress level
c) Blocked, by program
d) none of the above describes the experiment

10. D) Neither single nor double blind. E) Not an experiment.
Researchers would like to compare meditation and exercise to see which is more effective for reducing stress. One hundred people who suffer from high stress volunteer to participate in a study for ten weeks. Participants will either be given a 10-week course in meditation or will participate in a 10-week exercise program. The volunteers are randomly assigned to the two programs.
10. Suppose a psychologist measures their stress levels before and after the 10-week program, without being told who is which program. This experiment would be:
Single-blind as long as the participants are not told the results of the stress level measurements.
C) Double-blind as long as the participants are not told the results of the stress level measurements.
D) Neither single nor double blind.
E) Not an experiment.
B) Single-blind because the psychologist doesn’t know who is in which
program, but the participants do know.

11. Researchers would like to compare meditation and exercise to see which is more effective for reducing stress. One hundred people who suffer from high stress volunteer to participate in a study for ten weeks. Participants will either be given a 10-week course in meditation or will participate in a 10-week exercise program. The volunteers are randomly assigned to the two programs.
11. In this study, the stress level measurement after the 10-week program is an example of
A) A randomly assigned treatment.
B) An explanatory variable.
D) A normal variable.
E) A confounding variable.
C) A response variable.

12. D 2) A 3) E 4) B 5) A 6) D 7) B 8) D 9) A 10) B 11) C
Chapters 11, 12 and 13: Simulation, Sampling and Experimental Design
D 2) A 3) E
4) B 5) A 6) D
7) B 8) D 9) A
10) B 11) C