In: Statistics and Probability
Are the variances for incomes on the East Coast and the West Coast the same? Suppose that the table below shows the results of a study. Income is shown in thousands of dollars. Assume that both distributions are normal. Use a level of significance of 0.05.
East | West |
---|---|
37 | 70 |
46 | 125 |
29 | 43 |
81 | 52 |
74 | 44 |
52 | 89 |
116 | 87 |
66 |
Part (a)
State the null hypothesis.H0: σeast2 > σwest2H0: σeast2 = σwest2 H0: σeast2 < σwest2H0: σeast2 ≠ σwest2
Part (b)
State the alternative hypothesis.Ha: σeast2 < σwest2Ha: σeast2 = σwest2 Ha: σeast2 > σwest2Ha: σeast2 ≠ σwest2
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.F13, 13F7, 13 F7, 6F13, 6F6, 7
Part (f)
What is the test statistic? (Round your answer to two decimal places.)
Part (g)
What is the p-value? (Round your answer to four decimal places.)
Part (h)
Sketch a picture of this situation. Label and scale the horizontal axis, and shade the region(s) corresponding to the p-value.Part (i)
Indicate the correct decision ("reject" or "do not reject" the null hypothesis) and write appropriate conclusions.(i) Alpha (Enter an exact number as an integer, fraction, or decimal.)reject the null hypothesisdo not reject the null hypothesis
Since α < p-value, we reject the null hypothesis.Since α > p-value, we do not reject the null hypothesis. Since α > p-value, we reject the null hypothesis.Since α < p-value, we do not reject the null hypothesis.
There is sufficient evidence to conclude that the variances are different.There is not sufficient evidence to conclude that the variances are different.
conclusion: there is not sufficient evidence to conclude that variances are different.