To: sbaker@odu.edu
From: Thomas Meyer
tmeyer@ph.vccs.edu
276 656-0283
Patrick Henry Community College
Subject: Statistics - w/ Dr.Spencer Baker - Homework Assignment #4, Ch 138 - Problem 24, page 345.
Date: March 27, 2004
Use the following algorithm:
1. Get the data
2. Manipulate the data
To conduct the Independent Samples T-test at 95% confidence using two-tailed tests:
Having loaded the data
Click Analyze menu and choose Compare Means
Select Independent Sample T-test
Move gender into the grouping variable
group 1: enter 1 for males;
group 2: enter 2 for females;
Continue
Move Confer during math into the test variable
Options: 95%
__________________
Note: Right-click the
Independent Samples Test Output and heed the advice on when to use "Equal
Variances Assumed and "Equal Variances Not Assumed."
Having found the proper row in the Independent Samples Table, report the
t-statistic, degrees of freedom, and the probability of these occurring within a
two-tailed test.
If the value read from the significance of the two-tailed test exceeds the value
of the t-statistic, we cannot conclude that there is a difference between males
and females insofar as the variable on which they are being concluded, and we
are not able to reject the null hypothesis of "no difference" between men and
women.
If the value read from the significance of the two-tailed test is less than the
value of the t-statistic, we can conclude that there is a difference between
males and females insofar as the variable on which they are being concluded, and
we should reject the null hypothesis of "no difference" between men and women.
(This happens only in event D below. Apparently the perception that math
is a male domain is significant in causing results on math exams between men and
women, at least more so than would have been expected to occur by chance alone.)
Question:
The data from the data set named career.sav from your SPSS data bank contain
information that is related to career decisions of middle school and high school
students. In particular, students' perceptions of attitudes toward
mathematics for those important people in their environment may be important
components in selecting or deselecting particular careers. Because
attitudes are often a function of the gender of the person, participants were
coded by gender (1 = male, 2 = female) in the data set. Using your SPSS
data bank, perform an independent samples t-test using a two-tailed test with an
alpha of .05 to answer the following questions. Use the computer printout to
support your answers.
a. Do females and males differ in their confidence in doing mathematics (confmath)?
Answer:
Use Equal Variances assumed, because the Significance value is high, i.e., greater than .05.
Male/female differences regarding the variable "Confidence in Doing Math" produced a t-score of -1.474 with 198 degrees of freedom. Within a two-tailed test, the probability of this occurring was .142. Because the probability .142 exceeds the alpha value = .05, we cannot conclude that their is a difference between males and females insofar as their perception of the "Confidence in Doing Math" is concerned. We have not been able to reject the null hypothesis.
Question:
b. Do females and males differ in their perception of mother's
attitude toward mathematics (mother)?
Answer:
Use Equal Variances assumed.
Male/female differences regarding the variable "Perception of Mother's Attitude toward Math" produced a t-score of -.859 with 198 degrees of freedom. Within a two-tailed test, the probability of this occurring was .391. Because the probability .391 exceeds the alpha value = .05, we cannot conclude that their is a difference between males and females insofar as their perception of the "Perception of Mother's Attitude toward Math" is concerned. We have not been able to reject the null hypothesis.
Question:
c. Do females and males differ in their perception of father's
attitude toward mathematics (father)?
Answer:
Use Equal Variances assumed.
Male/female differences regarding the variable "Perception of Father's Attitude toward Math" produced a t-score of -.268 with 198 degrees of freedom. Within a two-tailed test, the probability of this occurring was .789. Because the probability .789 exceeds the alpha value = .05, we cannot conclude that their is a difference between males and females insofar as their perception of the "Perception of Father's Attitude toward Math" is concerned. We have not been able to reject the null hypothesis.
Question:
d. Do females and males differ in their perception of mathematics as a male domain (maledom)?
Answer:
Use Equal Variances not assumed.
Male/female differences regarding the variable "Perception of Math as a Male Domain" produced a t-score of -6.071 with 192.527 degrees of freedom. Within a two-tailed test, the probability of this occurring was .000. Because the probability .000 (probability < .001 is more appropriate since there are no events with a probability of zero) is less than the alpha value = .05, we can conclude that their is a difference between males and females insofar as their perception of the "Perception of Math as a Male Domain" is concerned. We have been able to reject the null hypothesis.
Question:
e. Do females and males differ in their perception of the usefulness of mathematics (useful)?
Answer:
Use equal variances not assumed because the Results Coach says if the Significance is high, i.e., greater than .05, use Equal Variances assumed. This is not the case here.
Male/female differences regarding the variable "Usefulness of mathematics" produced a t-score of -1.418 with 191.614 degrees of freedom. Within a two-tailed test, the probability of this occurring was .158. Because the probability .158 exceeds the alpha value = .05, we cannot conclude that their is a difference between males and females insofar as their perception of the "Usefulness of mathematics" is concerned. We have not been able to reject the null hypothesis.
Question:
f. Do females and males differ in their anxiety about doing mathematics (anxiety)?
Answer:
Use Equal Variances assumed.
Male/female differences regarding the variable "Anxiety about doing math" produced a t-score of -1.542 with 198 degrees of freedom. Within a two-tailed test, the probability of this occurring was .125. Because the probability .125 exceeds the alpha value = .05, we cannot conclude that their is a difference between males and females insofar as their perception of the "Anxiety about doing math" is concerned. We have not been able to reject the null hypothesis.
filename: StatHW3Ch13Prob24page345TomMeyer.doc
Tom Meyer
Thomas Meyer