Question

A poll was conducted to investigate opinions about global warming. The respondents who answered yes when asked if there is solid evidence that the earth is getting warmer were then asked to select a cause of global warming. The results are given in the accompanying data table. Use a 0.05 significance level to test the claim that the sex of the respondent is independent of the choice for the cause of global warming. Do men and women appear to​ agree, or is there a substantial​ difference?

Human activity Natural patterns ​Don't know

Male    309    143    59

Female 298 161 60

Identify the null and alternative hypotheses.

Ho​: (1)__________and (2)___________are (3)_____________

H1​: (4)__________and (5)___________are (6)_____________

Compute the test statistic.

_________________________​

(Round to three decimal places as​ needed.)

Find the critical​ value(s).

____________________

​(Round to three decimal places as needed. Use a comma to separate answers as​ needed.)

What is the conclusion based on the hypothesis​ test?

(7)_____________ Ho. There (8)___________sufficient evidence to warrant rejection of the claim that the sex of the respondent is independent of the choice for the cause of global warming. Men and women (9)__________to agree.

(1) Respondents who answered yes
   The choice for human activity
   The sex of the respondent
(2) the choice for the cause of global warming
   the respondents who answered no

the choice for natural patterns
(3) independent.
dependent.
(4) Respondents who answered yes
   The choice for human activity
   The sex of the respondent
(5) the respondents who answered no
   the choice for natural patterns
the choice for the cause of global warming
(6) independent.
   dependent.
(7) Reject
   Fail to reject
(8) is not
   is
(9) do not appear
   appear

Answer 1

Ho: The choice for human activity and The sex of the respondent are independent.

Ha: The choice for human activity and The sex of the respondent are dependent.

Applying chi square test of independence:

Expected	Ei=row total*column total/grand total	human	Natural	Do not known	Total
	Male	301.1	150.8	59.0	511
	female	305.9	153.2	60.0	519
	total	607	304	119	1030
chi square    χ2	=(Oi-Ei)2/Ei	human	Natural	Do not known	Total
	Male	0.205	0.405	0.000	0.6104
	female	0.202	0.399	0.000	0.6010
	total	0.4069	0.8046	0.0000	1.2115
test statistic X2=		1.211

for 2 df and 0.05 level,critical value χ2=

5.991

Fail to reject Ho. There is not sufficient evidence to warrant rejection of the claim that the sex of the respondent is independent of the choice for the cause of global warming. Men and women appear to agree