Chapter 7
15. In a particular country, it is known that college seniors report falling in love an
average of 2.20 times during their college years. A sample of five seniors, originally
from that country but who have spent their entire college career in the
United States, were asked how many times they had fallen in love during their
college years. Their numbers were 2, 3, 5, 5, and 2. Using the .05 significance
level, do students like these who go to college in the United States fall in love
more often than those from their country who go to college in their own country?
(a) Use the steps of hypothesis testing. (b) Sketch the distributions involved.
(c) Explain your answer to someone who is familiar with the Z test
(from Chapter 5) but is unfamiliar with the t test for a single sample.
Chapter 8
18. Twenty students randomly assigned to an experimental group receive an
instructional program; 30 in a control group do not. After 6 months, both groups
are tested on their knowledge. The experimental group has a mean of 38 on the
test (with an estimated population standard deviation of 3); the control group
has a mean of 35 (with an estimated population standard deviation of 5). Using
the .05 level, what should the experimenter conclude? (a) Use the steps of
hypothesis testing, (b) sketch the distributions involved, and (c) explain your
answer to someone who is familiar with the t test for a single sample but not
with the t test for independent means.
Chapter 9
18. A psychologist studying artistic preference randomly assigns a group of 45 participants
to one of three conditions in which they view a series of unfamiliar abstract
paintings. The 15 participants in the Famous condition are led to believe that
these are each famous paintings; their mean rating for liking the paintings is 6.5
(S = 3.5). The 15 in the Critically Acclaimed condition are led to believe that
these are paintings that are not famous but are very highly thought of by a group
of professional art critics; their mean rating is 8.5 (S = 4.2 ). The 15 in the Control
condition are given no special information about the paintings; their mean rating
is 3.1 (S = 2.9 ). Does what people are told about paintings make a difference
in how well they are liked? Use the .05 level. (a) Use the steps of hypothesis testing; (c) figure the effect size for the study; (d) explain your answer to part (a) to someone who is familiar with the t test for independent means but is unfamiliar with analysis of variance
Chapter 11
11. Make up a scatter diagram with 10 dots for each of the following situations:
(a) perfect positive linear correlation, (b) large but not perfect positive linear
correlation, (c) small positive linear correlation, (d) large but not perfect negative
linear correlation, (e) no correlation, (f) clear curvilinear correlation.
13. Four young children were monitored closely over a period of several weeks to
measure how much they watched violent television programs and their amount
of violent behavior toward their playmates. The results were as follows:
|
Child Code number
|
Weekly Viewing of
Violent TV (hours
|
Number of Violent or Aggressive
Acts Toward Playmates
|
|
G3368
|
14
|
9
|
|
R8904
|
8
|
6
|
|
C9890
|
6
|
1
|
|
L8722
|
12
|
8
|
(a) Make a scatter diagram of the scores; (b) describe in words the general pattern of correlation, if any; (c) figure the correlation coefficient; (d) figure whether the correlation is statistically significant
(use the .05 significance level, two-tailed); (e) explain the logic of what
you have done, writing as if you are speaking to someone who has never heard
of correlation (but who does understand the mean, deviation scores, and hypothesis
testing); and (f) give three logically possible directions of causality, indicating
for each direction whether it is a reasonable explanation for the correlation
in light of the variables involved (and why).
Can anyone help me?
