Discuss the below in detail:
Q: A study claims that the percentage of incomes that people pay in total taxes is the same for different income levels. A "random sample" of tax data showing the average taxes paid in six different cities is given below; the column heading is the income level.
a) Form an explicit null hypothesis and perform an ANOVA test to evaluate this claim.
b) Discuss some difficulties with this "random" sample - since we are picking cities, how does it affect the statement of the null hypothesis?
$25,000 |
$50,000 |
$75,000 |
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income level |
income level |
income level |
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| Des Moines, IA |
7.4 |
8.2 |
9 |
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|
|
|
|
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| Charleston, WV |
6.8 |
7.1 |
8.5 |
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|
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| Memphis, TN |
6.9 |
5.8 |
6 |
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| Sioux Fall, SD |
7.3 |
6.4 |
7.1 |
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| Philadelphia, PA |
15.8 |
15.2 |
15.1 |
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|
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| Chicago, IL |
11.8 |
11.9 |
12.4 |