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

men 320 156 39

female 336 142 37

compute test statistic and critical value

What is the conclusion based on the hypothesis​ test?

▼

Upper H 0

.

There

▼

is

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

do not appear

to agree.

Answer 1

Ho: sex of the respondent is independent of the choice for the cause of global warming

Ha: sex of the respondent is not independent of the choice for the cause of global warming

Chi-Square Test of independence
	Observed Frequencies
	natural	patterns	don’t know				Total
men	320	156	39				515
female	336	142	37				515
Total	656	298	76				1030
	Expected frequency of a cell = sum of row*sum of column / total sum
	Expected Frequencies
	natural	patterns	don’t know				Total
men	656*515/1030=328	298*515/1030=149	76*515/1030=38				515
female	656*515/1030=328	298*515/1030=149	76*515/1030=38				515
Total	656	298	76				1030
(fo-fe)^2/fe	natural	patterns	don’t know				total
men	0.195	0.329	0.026				0.5503
female	0.195	0.329	0.026				0.550

Chi-Square Test Statistic,χ² = Σ(fo-fe)^2/fe =   1.1006  
      
Level of Significance =   0.05  
Number of Rows =   2  
Number of Columns =   3  
Degrees of Freedom=(#row - 1)(#column -1) = (2- 1 ) * ( 3- 1 ) =   2  
      
p-Value =   0.5768   [Excel function: =CHISQ.DIST.RT(χ²,df) ]
Decision:    p value > α , do not 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

do not appear

to agree.