Chapter 1
 A teacher wishes to know whether the males in his/her class have more
favorable attitudes toward gun control than do the females. All students
in the class are given a questionnaire about gun control and the mean
responses of the males and the females are compared. Is this an example
of descriptive or inferential statistics?
 A medical researcher is testing the effectiveness of a new drug for
treating Parkinson's disease. Ten subjects with the disease are given
the new drug and 10 are given a placebo. Improvement in symptomology
is measured. What would be the roles of descriptive and inferential
statistics in the analysis of these data?
 What are the advantages and disadvantages of graphical as opposed
to numerical approaches to descriptive statistics?
 Distinguish between random and stratified sampling?
 A study is conducted to determine whether people learn better with
spaced or massed practice. Subjects volunteer from an introductory psychology
class. The first 10 subjects who volunteer are assigned to the massedpractice
condition; the next 10 are assigned to the spacedpractice condition.
Discuss the consequences and seriousness of each of the following two
kinds of nonrandom sampling: (1) Subjects are not randomly sampled
from some specified population and (2) subjects are not randomly assigned
to conditions. In general, which type of nonrandom sampling is more
serious?
 Define independent and dependent variables.
 Categorize the following variables as being qualitative or quantitative:
Response time
Rating of job satisfaction
Favorite color
Occupation aspired to
Number of words remembered
 Specify the level of measurement used for the items in Question 7.
 Categorize the variables in Question 7 as being continuous or discrete.
 Are Greek letters used for statistics or for parameters?
 When would the mean score of a class on a final exam be considered
a statistic? When would it be considered a parameter?
 An experiment is conducted to examine the effect of punishment on
learning speed in rats. What are the independent and dependent variables?
 For the numbers 1, 2, 4, 8
Compute:
ΣX
ΣX^{2
}(ΣX) ^{2
}
 ΣX = 7 and ΣX²
= 21. A new variable Y is created by multiplying each X by 3. What are
ΣY and ΣY²
equal to ?
Selected Answers
