In: Statistics and Probability
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
Given table data is as below
------------------------------------------------------------------ calculation formula for E table matrix
------------------------------------------------------------------ expected frequencies calculated by applying E - table matrix formulae
------------------------------------------------------------------ calculate chisquare test statistic using given observed frequencies, calculated expected frequencies from above
------------------------------------------------------------------ set up null vs alternative as null, Ho: no relation b/w X and Y OR X and Y are independent alternative, H1: exists a relation b/w X and Y OR X and Y are dependent level of significance, α = 0.05 from standard normal table, chi square value at right tailed, ᴪ^2 α/2 =5.991 since our test is right tailed,reject Ho when ᴪ^2 o > 5.991 we use test statistic ᴪ^2 o = Σ(Oi-Ei)^2/Ei from the table , ᴪ^2 o = 1.211 critical value the value of |ᴪ^2 α| at los 0.05 with d.f (r-1)(c-1)= ( 2 -1 ) * ( 3 - 1 ) = 1 * 2 = 2 is 5.991 we got | ᴪ^2| =1.211 & | ᴪ^2 α | =5.991 make decision hence value of | ᴪ^2 o | < | ᴪ^2 α | and here we do not reject Ho ᴪ^2 p_value =0.546 ANSWERS --------------- null, Ho: no relation b/w X and Y OR X and Y are independent alternative, H1: exists a relation b/w X and Y OR X and Y are dependent test statistic: 1.211 critical value: 5.991 p-value:0.546 decision: do not reject Ho |
we do not have enough evidence to support the claim that the sex of the respondent is independent of the choice for the cause of global warming. Men and women