A graphing calculator is recommended. A grassroots group opposed to a proposed i
ID: 3376077 • Letter: A
Question
A graphing calculator is recommended.
A grassroots group opposed to a proposed increase in the gas tax claimed that the increase would hurt working-class people the most, since they commute the farthest to work. Suppose that the group randomly surveyed 24 individuals and asked them their daily one-way commuting mileage. The results are below. Using a 5% significance level, test the hypothesis that the three mean commuting mileages are the same. (Let 1 = Working-class, 2 = Professional (middle incomes), and 3 = Professional (wealthy).)
Part (a)
State the null hypothesis. Choose 1 or 2
1. H0: ?1 = ?2 = ?3H0:
2. At least two of the group means ?1, ?2, ?3 are not equal.
Part (b)
State the alternative hypothesis. Choose 1 or 2
1. Ha: At least two of the group means ?1, ?2, ?3 are not equal.
2. Ha: ?1 = ?2 = ?3
Part (c)
Enter an exact number as an integer, fraction, or decimal.
df(num) =
Part (d)
Enter an exact number as an integer, fraction, or decimal.
df(denom) =
Part (e)
State the distribution to use for the test. Choose 1 2 3 4 5
1. F21, 23
2. F21, 2
3. F2, 23
4. F2, 21
5. F23, 21
What is the test statistic? (Round your answer to two decimal places.)
____________
What is the p-value? (Round your answer to four decimal places.)
__________
Explain what the p-value means for this problem. Choose answer
1. If H0 is true, then there is a chance equal to the p-value that the value of the test statistic will be equal to or less than the calculated value.
2.If H0 is false, then there is a chance equal to the p-value that the value of the test statistic will be equal to or greater than the calculated value.
3.If H0 is false, then there is a chance equal to the p-value that the value of the test statistic will be equal to or less than the calculated value.
4. If H0 is true, then there is a chance equal to the p-value that the value of the test statistic will be equal to or greater than the calculated value.
Working-class Professional (middle incomes) Professional (wealthy) 16.9 16.0 8.4 26.2 16.7 5.4 48.7 21.8 4.4 9.2 7.1 11.7 65.2 8.6 10.6 46.5 1.9 28.3 19.0 5.9 14.8 50.4 13.0 8.9Explanation / Answer
Part (a)
Correct option : 1. H0: ?1 = ?2 = ?3
Part (b)
Correct option : 1. Ha: At least two of the group means ?1, ?2, ?3 are not equal.
Part (c)
df(num) = 2
Part (d)
df(denom) = 21
Part (e)
Correct option : 4. F2, 21
Now, we obtain the following ANOVA table after analysis:
Here , Test statistic = 9.06 (Two decimal places)
Here, P-value = 0.0015 ( Four decimal places)
The p-value means for this problem :
Correct option : 4. If H0 is true, then there is a chance equal to the p-value that the value of the test statistic will be equal to or greater than the calculated value.
ANOVA Source of Variation SS df MS F P-value F crit Between Groups 3019.568 2 1509.784 9.05867 0.001457 3.4668 Within Groups 3500.013 21 166.6673 Total 6519.58 23