In: Statistics and Probability
In a study of media usage versus education level (American Demographics, Vol. 17, No. 6), an index was used to measure media usage, where a measurement of 100 represents the U.S. average. Values above 100 represent above-average media usage.
Media | |||||
Education Level | Cable Network |
Prime-Time TV |
Radio | Newspaper | Magazine |
Less than high school | 80 | 112 | 87 | 76 | 85 |
High school graduate | 103 | 105 | 100 | 99 | 101 |
Some College | 107 | 94 | 106 | 105 | 107 |
College graduate | 108 | 90 | 106 | 116 | 108 |
Source: From American Demographics, Vol. 17, No. 6. Reprinted with permission, copyright 1995 American Demographics, Ithaca, NY. |
Minitab Printout for Media/Education Data | |||||
Analysis of Variance for Index | |||||
Source | DF | SS | MS | F | P |
Edu | 3 | 961 | 320 | 2.96 | 0.075 |
Media | 4 | 5 | 1 | 0.01 | 1.000 |
Error | 12 | 1299 | 108 | ||
Total | 19 | 2264 |
(a) List the factors and the number of levels of each factor. (Select all that apply.)
media usage, with two levels
education level, with three levels
media type, with five levels
education level, with four levels
school, with four levels
media type, with four levels
(b) Assume there is no interaction between the factors. Use two-way
ANOVA and the following Minitab printout to determine if there is a
difference in population mean index based on education. Use
α = 0.1.
STEP 1: |
State the hypotheses. No difference in population mean index according to education level. At least two education levels have different mean indices. All education levels have different mean indices. At least two types of media have different population mean indices. All types of media have different population mean indices. No difference in population mean index by media type. H1: ---Select--- All education levels have different mean indices. At least two education levels have different mean indices. No difference in population mean index according to education level. At least two types of media have different population mean indices. All types of media have different population mean indices. No difference in population mean index by media type. |
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STEP 2: | Find the test statistic and P-value.
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STEP 3: |
State your conclusion. At the 10% level of significance, ---Select--- do not reject OR reject H0 for education level. The data ---Select--- do not indicate any differences OR indicate differences in population mean index according to education level. |
(c) Determine if there is a difference in population mean index based on media. Use α = 0.1.
STEP 1: |
State the hypotheses. At least two types of media have different population mean indices. All education levels have different mean indices. All types of media have different population mean indices. At least two education levels have different mean indices. No difference in population mean index by media type. No difference in population mean index according to education
level. H1: ---Select--- No difference in population mean index by media type. No difference in population mean index according to education level. All types of media have different population mean indices. All education levels have different mean indices. At least two education levels have different mean indices. At least two types of media have different population mean indices. |
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STEP 2: | Find the test statistic and P-value.
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STEP 3: | State your conclusion. At the 10% level of significance, ---Select--- do not reject OR reject H0 for media. The data ---Select--- do not indicate any differences OR indicate differences in population mean index according to media type. |
(a)
media type, with five levels
education level, with four levels
(b) STEP-1
For difference testing, we assume null hypothesis as there is no difference between means and for alternate hypothesis, we assume that at least two levels are different
Ho: No difference in population mean index according to education level.
Ha: At least two education levels have different mean indices.
STEP-2 using the given data output table
we get
F = 2.96
p value = 0.075
STEP 3:- p value is less than 0.10 level of significance, rejecting the null hypothesis.
At the 10% level of significance, reject H0 for education level.
The data indicate differences in population mean index according to education level.
(C) STEP 1
H0: No difference in population mean index by media type.
H1: At least two types of media have different population mean indices
STEP-2 using the given data output table
we get
F = 0.01
p value = 1.000
STEP 3:- p value is greater than 0.10 level of significance, failing to reject the null hypothesis.
At the 10% level of significance, do not
reject H0 for media.
The data do not indicate any differences in
population mean index according to media type.