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.)
school, with four levels
education level, with three levels
education level, with four levels
media usage, with two levels
media type, with five 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
? = 0.05.
STEP 1: |
State the hypotheses. All types of media have different population mean indices. At least two types of media have different population mean indices. No difference in population mean index according to education level. All education levels have different mean indices. At least two education levels have different mean indices. No
difference in population mean index by media type. At least two types of media have different population mean indices. No difference in population mean index according to education level. 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. All
education levels have different 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 5% level of significance, ---Select--- do not reject/reject H0 for education level. The data ---Select--- do not indicate any difference/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 ? = 0.05.
STEP 1: |
State the hypotheses. No difference in population mean index by media type. All education levels have different mean indices. No difference in population mean index according to education level. All types of media have different population mean indices. At least two types of media have different population 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. No difference in population mean index by media type. 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. |
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STEP 2: | Find the test statistic and P-value.
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STEP 3: | State your conclusion. At the 5% level of significance, ---Select One--- reject/do not reject H0 for media. The data ---SelectOne--- do not indicate any differences/indicate differences in population mean index according to media type. |
Solution :--
(a) List the factors and the numbers of levels of each facor .
Education level , with four levels.
(i.e Educational Level - less than high school , High school graduate , Some College , College Graduate ).
Media type , with five levels .
(i.e. Media Type - Cable Network, Prime_Time TV , Radio , Nespaper , Magzine )
(b) Population mean index based On education.
1). Hypothesis --
Ho : No difference in population mean index according to education level .
and ,
H1 : At least two education levels have different mean indices.
2). Test Statistics and P- value :-
F = 2.96
P- Value = 0.075
3). Conclusion :
At 5% level of significance ,
We do not reject Ho for eduactional level .
We conclude that , No difference in population mean index according to education level.
( c ) population mean index based on media :
1). Hypothesis :
Ho : No difference in population mean index by media type.
and
H1 : At least two types of media have different population mean indices.
2). Test Statistic and p-value :
F = 0.01
p-value = 1.000
3). Conclusion :
At 5% level of significance ,
We do not reject Ho for eduactional level .
We conclude that , No difference in population mean index by media type .