Question

Pro-choice/Pro-life and Region of the Country: The results of a 2013 Gallup poll about people's position on abortion (pro-life or pro-choice) by region of the country are summarized in the contingency table below.

Observed Frequencies: O_i's

	East	Midwest	South	West	Totals
Pro-Choice	215	96	181	184	676
Pro-Life	191	86	239	208	724
Totals	406	182	420	392	1400

The Test: Test whether or not there is a dependent relationship between abortion stance and region. Conduct this test at the 0.05 significance level.

(a) What is the null hypothesis for this test?

H₀: Opinion on abortion and region of the country are independent variables.

H₀: Opinion on abortion and region of the country are dependent variables.      

(b) What is the value of the test statistic? Round to 3 decimal places unless your software automatically rounds to 2 decimal places.

χ²

=  

(c) Use software to get the P-value of the test statistic. Round to 4 decimal places unless your software automatically rounds to 3 decimal places.
P-value =  

(d) What is the conclusion regarding the null hypothesis?

reject H₀

fail to reject H₀     

(e) Choose the appropriate concluding statement.

We have proven abortion stance and region are independent.

The evidence suggests that there is a dependent relationship between abortion stance and region.     

There is not enough evidence to conclude that there is a dependent relationship between abortion stance and region.

Answer 1

Tabulated Statistics: C1, Worksheet columns

Rows: C1   Columns: Worksheet columns

	East	Midwest	South	West	All
Pro-Choice	215	96	181	184	676
	196.0	87.9	202.8	189.3
Pro-Life	191	86	239	208	724
	210.0	94.1	217.2	202.7
All	406	182	420	392	1400

Cell Contents
      Count
      Expected count

Chi-Square Test

	Chi-Square	DF	P-Value
Pearson	9.813	3	0.020

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a) H₀: Opinion on abortion and region of the country are independent variables.

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c) P-value = 0.020

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d) Reject Ho

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e) The evidence suggests that there is a dependent relationship between abortion stance and region.