- Fact Formula for the Chi-Square Goodne ce their an (0 - E) X = = E Momon ngual to the number of categories minus 1, and where

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Topic Video
Question
s w 2. If all the expected frequencies are not equal, then the expected frequency E can be
quencies are called the observed frequencies. The frequencies obtained by calculation
riT Since the frequencies for each flavor were obtained from a sample, these actual fre-
these data:
Section 11-1 Test for Goodness of Fit
591
Cherry
Strawberry
32
Orange
28
Lime
Grape
16
14
10
(as if there were no preference) are called the expected frequencies.
To calculate the expected frequencies, there are two rules to follow.
1. If all the expected frequencies are equal, the expected frequency E can be calculated
by using E = n/k, where n is the total number of observations and k is the number
of categories.
calculated by E = n · p, where n is the total number of observations and p is the
probability for that category.
avel an
oig
boog an expect each flavor to be selected with equal frequency. In this case, the equal frequency is
bn nosmi 100/5 = 20. That is, approximately 20 people would select each flavor. A completed table
to onoupsl bo for the test is shown.
Looking at the new fruit flavors example, if there were no preference, you would
s ol uliy borog t
Frequency
Cherry
Strawberry
Orange
Grape
Lime
ni bo in Observed
Expected
32
10
28
20
16
20
14
20
20
20
The observed frequencies will almost always differ from the expected frequencies
due to sampling error; that is, the values differ from sample to sample. But the question
is: Are these differences significant (a preference exists), or are they due to chance? The
chi-square goodness-of-fit test will enable the researcher to determine the answer.
Defore computing the test value, you must state the hypotheses. The null hypothesis
shoul be a statement indicating that there is no difference or no change. For this exam-
ple, the bypotheses are as follows:
He: Consumers show no preference for flavors of the fruit soda.
H: Consumers show a preference.
Next, we need a measure of discrepancy between the observed values O and the
expected values E, so we use the test statistic for the chi-square goodness-of-fit test.
TInteresting Fact
Formula for the Chi-Square Goodness-of-Fit Test
E)
(0
Men begin to lose their
hearing more than
30 years before women.
The difference may be
due to males' more fre-
quent exposure to such
noisy machines as
power tools and
lawnmowers.
E
with degrees of freedom equal to the number of categories minus 1, and where
O = observed frequency
E = expected frequency
Notice that the value of the test statistic is based on the difference between the observed
values and the expected values. If the observed values are significantly different from the
expected values, then there is enough evidence to reject the null hypothesis.
When there is perfect agreement between the observed and the expected values
= 0. Also, ? can never be negative. Finally, the test is right-tailed because
u. Good fir" and "Hi: Not a good fit" mean that x² will be small in the first case and
large in the second case.
d In the goodness-of-fit test, the degrees of freedom are equal to the number ec
11-3
Transcribed Image Text:s w 2. If all the expected frequencies are not equal, then the expected frequency E can be quencies are called the observed frequencies. The frequencies obtained by calculation riT Since the frequencies for each flavor were obtained from a sample, these actual fre- these data: Section 11-1 Test for Goodness of Fit 591 Cherry Strawberry 32 Orange 28 Lime Grape 16 14 10 (as if there were no preference) are called the expected frequencies. To calculate the expected frequencies, there are two rules to follow. 1. If all the expected frequencies are equal, the expected frequency E can be calculated by using E = n/k, where n is the total number of observations and k is the number of categories. calculated by E = n · p, where n is the total number of observations and p is the probability for that category. avel an oig boog an expect each flavor to be selected with equal frequency. In this case, the equal frequency is bn nosmi 100/5 = 20. That is, approximately 20 people would select each flavor. A completed table to onoupsl bo for the test is shown. Looking at the new fruit flavors example, if there were no preference, you would s ol uliy borog t Frequency Cherry Strawberry Orange Grape Lime ni bo in Observed Expected 32 10 28 20 16 20 14 20 20 20 The observed frequencies will almost always differ from the expected frequencies due to sampling error; that is, the values differ from sample to sample. But the question is: Are these differences significant (a preference exists), or are they due to chance? The chi-square goodness-of-fit test will enable the researcher to determine the answer. Defore computing the test value, you must state the hypotheses. The null hypothesis shoul be a statement indicating that there is no difference or no change. For this exam- ple, the bypotheses are as follows: He: Consumers show no preference for flavors of the fruit soda. H: Consumers show a preference. Next, we need a measure of discrepancy between the observed values O and the expected values E, so we use the test statistic for the chi-square goodness-of-fit test. TInteresting Fact Formula for the Chi-Square Goodness-of-Fit Test E) (0 Men begin to lose their hearing more than 30 years before women. The difference may be due to males' more fre- quent exposure to such noisy machines as power tools and lawnmowers. E with degrees of freedom equal to the number of categories minus 1, and where O = observed frequency E = expected frequency Notice that the value of the test statistic is based on the difference between the observed values and the expected values. If the observed values are significantly different from the expected values, then there is enough evidence to reject the null hypothesis. When there is perfect agreement between the observed and the expected values = 0. Also, ? can never be negative. Finally, the test is right-tailed because u. Good fir" and "Hi: Not a good fit" mean that x² will be small in the first case and large in the second case. d In the goodness-of-fit test, the degrees of freedom are equal to the number ec 11-3
The test described shows whether or not there is a ?
a.
Relationship
b.
Preference
Page 591
Dependence
С.
d.
None of these
thore is a ?
Transcribed Image Text:The test described shows whether or not there is a ? a. Relationship b. Preference Page 591 Dependence С. d. None of these thore is a ?
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Propositional Calculus
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman