Chapter 1-2

Question 1

Dr. Hare tested the hypothesis that understanding statistics helps people to make more intelligent medical decisions. He randomly assigned 1,000 medical students to a statistics course or a medical ethics course. At the end of the course, he had all subjects read an article, written in English, about the prevention of heart attacks and asked them to answer 10 questions with right or wrong answer choices about what habits are best for preventing heart attacks. He used SPSS to analyze each group’s average number of correct questions.
What is the independent variable?

Select one:
a. number of correct questions
b. the type of course
c. reading speed
d. the age of the participants

Answer 1

b. the type of course

Question 2

What is the dependent variable in Dr. Hare’s study?

Select one:
a. the type of course
b. reading speed
c. the age of the participants
d. number of correct questions

Answer 2

d. number of correct questions

Question 3

What kind of study did Dr. Hare conduct?

Select one:
a. quasi-experiment
b. descriptive
c. true experiment
d. correlational

Answer 3

c. true experiment

Question 4

Dr. Hare wants to use his results to make a general conclusion about all people. He will use

Select one:
a. inferential statistics
b. descriptive statistics
c. a bar graph
d. all of the other answers are correct

Answer 4

d. all of the other answers are correct

Question 5

The group of people who participate in Dr. Hare’s study is called the _______; the group of people from which that group is chosen is called the___________.

Select one:
a. subjects; pool
b. sample; population
c. population; sample
d. subjects; population

Answer 5

b. sample; population

Question 6

A potential confounding variable in Dr. Hare’s experiment is

Select one:
a. all of the other answers are correct
b. political affiliation
c. personal history of heart attacks
d. not being a native English speaker

Answer 6

a. all of the other answers are correct

Question 7

The most important method Dr. Hare used for eliminating confounding variables is

Select one:
a. use of a large sample
b. use of two groups
c. inferential statistics
d. random assignment

Answer 7

d. random assignment

Question 8

The most important method Dr. Hare used for reducing sampling error is

Select one:
a. use of a large sample
b. use of two groups
c. random assignment
d. inferential statistics

Answer 8

a. use of a large sample

Question 9

The dependent variable in Dr. Hare’s experiment is?

Select one:
a. discrete and ratio
b. continuous and interval
c. discrete and nominal
d. continuous and ratio

Answer 9

a. discrete and ratio

Question 10

Which of the following variables is NOT measured on an ordinal scale?

Select one:
a. reaction time to a 2-choice stimulus
b. severity of aggression as mild (push or shove), moderate (hit on head or stomach) , or extreme (slash with knife)
c. quality of musical composition rated as potential hits, album music, or failures.
d. ranking of divers’ dives (1st, 2nd, 3rd, etc)

Answer 10

c. quality of musical composition rated as potential hits, album music, or failures.

Question 11

When is a scatterplot is used?

Select one:
a. more than one of the other answers is correct
b. for all non-experimental designs
c. to compare 2 independent variables
d. to compare 2 dependent variables

Answer 11

d. to compare 2 dependent variables

Question 12

Five students are given a test, and their scores are 101, 130, 5, 99, 108. What is ΣX?

Answer 12

443

Question 13

For the same set of data, which of the following expressions would yield 48,591?

a. Σ(X+5000)
b. ΣX2
c. (ΣX)2

Answer 13

b. ΣX2

Question 14

Which of the following pairs of IPT terms contains one construct and its operational definition

Select one:
a. Construct: information channel; Operational definition: number of IPT questions correct
b. Construct: cues about static social smiles; Operational definition: inter-personal perception
c. Construct: audio-video presentation; Operational definition: text presentation
d. Construct: information channel; Operational definition: text or audio-visual presentation

Answer 14

d. Construct: information channel; Operational definition: text or audio-visual presentation

Question 15

Which of the following were independent variables in the IPT experiment we did in class?

Select one:
a. number of static facial emotions perceived correctly; type of social interaction to judge
b. text presentation; audio-video presentation
c. the type of social interaction to judge; information channel
d. number of IPT questions correct; type of static smile

Answer 15

c. the type of social interaction to judge; information channel

Question 16

Which of the following experimental variables from our IPT experiment will be entered as a single column in the Data View Tab of SPSS, and which will be entered in multiple columns?

Select one:
a. Single column: information channel; Multiple columns: static facial cues
b. Single column: information channel; Multiple columns: type of social interaction judged
c. Single column: type of social interaction judged; Multiple columns: accuracy for perceiving static social smiles
d. Single column: Cueing about static smiles; Multiple columns: information channel

Answer 16

b. Single column: information channel; Multiple columns: type of social interaction judged

Question 17

Which of the following hypotheses about our IPT data would be answered with a non-experimental design?

Select one:
a. Providing cues about social messages encoded in static smiling faces improves observers’ ability to identify those social messages.
b. The type of social interaction viewed affects the accuracy of perceiving it.
c. The non-verbal information channel affects the accuracy of perceiving dynamic social interactions.
d. More than one of the other answers is correct

Answer 17

b. The type of social interaction viewed affects the accuracy of perceiving it.

Question 18

1. A study is conducted in which 12 participants press a button when they hear the first dirty word in a list of words. The time it takes them to press the button is recorded (their reaction times, in msec).
   In the above table, 750 msec is

Select one:
a. the 50th percentile
b. all of the other answers are correct
c. the independent variable
d. a continuous variable

Answer 18

a. the 50th percentile

Question 19

1. The relative frequency of 750 msec is

Answer 19

0.166

Question 20

1. The value Σp for all scores, where p is relative frequency (or probability) is

Answer 20

1

Question 21

If a set of data has its highest score is X = 93 and lowest score is X = 52, should a regular or a grouped distribution be used, and what interval width that would be most appropriate?

Select one:
a. Ungrouped, Interval=4
b. Grouped, Interval width=10
c. Ungrouped, Interval width=1
d. Grouped, Interval width= 4

Answer 21

d. Grouped, Interval width= 4

Question 22

If I gave a test and 80% of the students got A’s and B’s, 15% got C’s, and 5% got D’s or F’s, using a scale where A= 90 or better, B=80-89, etc., then my distribution is:

Select one:
a. Positively skewed
b. U-shaped
c. normal
d. none of the other answers is correct

Answer 22

d. none of the other answers is correct

Question 23

Which of the following best shows the shape of a distribution?

Select one:
a. bar graph and the 50th percentile point
b. range and 50th percentile point
c. frequency polygon and interval with the highest frequency
d. bar graph and category with the highest frequency

Answer 23

c. frequency polygon and interval with the highest frequency

Question 24

A consumer conducting a survey of car brands spends an hour at a busy intersection and writes down the brand of each car. What type of graph should she use?

Select one:
a. scatterplot
b. discrete
c. bar graph
d. histogram

Answer 24

c. bar graph

Question 25

100 subjects are selected for a study to see if meditation improves extra-sensory perception (ESP). 50 subjects are assigned to a group that is led through a 10-minute meditation period, and 50 control subjects converse with the experimenter for 10 minutes. Then, each subject is instructed to flip a coin 10 times, but before each flip they have to guess whether it will be heads or tails, and the experimenter counts the number of times they are right.
The number of guesses that each subject would be correct by chance is

Answer 25

5

Question 26

2. The following is a grouped distribution of scores on an exam graded in increments of 1 point.

The proportion of students who scored between 70 and 74 is

Answer 26

2

Question 27

2. The percentile rank of a score of 65 is ___________

Select one:
a. 0.24%
b. 0.24
c. 42%
d. 8

Answer 27

c. 42%

Question 28

2. The value in the cell marked AAA is

Answer 28

45

Question 29

2. The relative frequency of scores below the most frequent interval is_____, and the relative frequency of scores higher than the most frequent interval is______.

Select one:
a. below= 0.377, above= 0.422
b. below= 0.422, above= 0.377
c. below= 19, above= 17
d. none of the other answers is correct

Answer 29

b. below= 0.422, above= 0.377

Question 30

2. The lower and upper real limits of the interval with the highest scores are ___(LRL) and ____(URL).

Select one:
a. LRL= 94; URL=99
b. LRL= 69.5; URL=74.5
c. LRL= 94.25; URL=99.25
d. LRL= 94.5; URL=99.5

Answer 30

d. LRL= 94.5; URL=99.5

Question 31

3. Here are two frequency histograms from two studies of reading comprehension in third grade students:
   Which study has more individual differences?

Select one:
a. Study 1
b. Study 2
c. Neither study
d. Both studies are the same

Answer 31

a. Study 1

Question 32

3. Which study has a lower sampling error (would come closer to estimating the population)?

Select one:
a. Study 1
b. Study 2
c. Neither study
d. Both studies are the same

Answer 32

a. Study 1

Question 33

3. What is the best explanation for the answer to the previous question?

Select one:
a. Pick the study with the least individual differences
b. Pick the study with the most subjects
c. There wasn’t enough information to decide the best explanation
d. Pick the study with the least individual differences and the most subjects

Answer 33

b. Pick the study with the most subjects

Question 34

4. The following graphs summarize the experimental data:
   Select all of the choices that describe errors in the summary plots

Select one or more:
a. Labels are missing or deficient
b. The histogram bars should be grouped
c. At least one of the frequencies is plotted incorrectly
d. There should be space between the histogram bars

Answer 34

a. Labels are missing or deficient
c. At least one of the frequencies is plotted incorrectly

Question 35

4. Choose all reasons why the mean values(the right graph) are plotted as a bar graph?

Select one or more:
a. There is no good reason for using a bar graph; they should be plotted as a histogram with bars that touch.
b. The levels of the independent variable are discrete categories
c. Interchanging the levels of the independent variable on the X axis will not affect the conditions
d. The levels of the independent variable differ on a ratio scale (amount of meditation time)

Answer 35

b. The levels of the independent variable are discrete categories
c. Interchanging the levels of the independent variable on the X axis will not affect the conditions

Question 36

4. What is best expression of the statistical hypothesis?

Select one:
a. Meditation will affect ESP
b. The mean # Correct guesses will be higher in the Meditation group than the Control group.
c. H0: The population mean # Correct guesses will not be affected by Meditation
H1: The population mean # Correct guesses will be improved by Meditation
d. H0: μMeditation ≤ μControl
H1: μMeditation > μControl

Answer 36

d. H0: μMeditation ≤ μControl
H1: μMeditation > μControl

Question 37

4. Select all the choices that are relevant for deciding about the research hypothesis.

Select one or more:
a. The Control group has a lower proportion of subjects scoring above chance
b. The Control group has a lower mean number of correct answers.
c. One of the histograms has a skewed distribution
d. The difference between groups (7.2 versus 5.6) is larger than the differences between subjects

Answer 37

a. The Control group has a lower proportion of subjects scoring above chance
b. The Control group has a lower mean number of correct answers.
c. One of the histograms has a skewed distribution