Support of Background Checks by Political Party: In April of 2013, the U.S. Sena

Question

Support of Background Checks by Political Party: In April of 2013, the U.S. Senate did not pass a bill to expand background checks to all gun sales despite popular approval of the idea. Gallup conducted a poll on this issue with the question: Would you vote for or against a law to require background checks for all gun sales?. The results by political affiliation are summarized in the contingency table below.

Observed Frequencies: Oi's

The Test: Test for a dependent relationship between party affiliation and opinion on expanded background checks. Conduct this test at the 0.01 significance level.

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

H0: Party affiliation and opinion on expanded background checks are independent variables.H0: Party affiliation and opinion on expanded background checks 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.

2

=  

(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 H0fail to reject H0    

(e) Choose the appropriate concluding statement.

We have proven that opinion on expanded background checks and party affiliation are independent.The evidence suggests that there is a dependent relationship between party affiliation and opinion on expanded background checks.    There is not enough evidence to conclude that party affiliation and opinion on expanded background checks are dependent.

Republican Independent Democrat Totals For Checks   291   75     303     669   Against Checks   77   13     41     131   Totals   368     88     344     800  

Explanation / Answer

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

H0: Party affiliation and opinion on expanded background checks are independent variables.

(b)here we use chi-squre test and chi-square=sum((O-E)2/E)=10.715 with (r-1)(c-1)=(2-1)(3-1)=2 df

(c)P-value= =( using ms-excel command=chidist(10.715,5))=0.005

(d) reject H0,

As p-value is less than alpha=0.01

(e) The evidence suggests that there is a dependent relationship between party affiliation and opinion on expanded background checks.

Republican Independent Democrat Totals For Checks   291   75     303     669   Against Checks   77   13     41     131   Totals   368     88     344     800 Observed(O) Expected(E) Expected(E) (O-E) (O-E)2/E 291 669*368/800 307.74 -16.74 0.910599 75 669*88/800 73.59 1.41 0.027016 303 669*344/800 287.67 15.33 0.816939 77 131*368/800 60.26 16.74 4.650309 13 131*88/800 14.41 -1.41 0.137967 41 131*344/800 56.33 -15.33 4.172002 sum 800 800 -2.5E-14 10.71483

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.