In: Math
Show how to answer this in EXCEL ONLY, NO megastat or minitab, etc.. Please highlight what data tools or formulas were used.
A survey investigated the public’s attitude toward the federal deficit. Each sampled citizen was classified as to whether he or she felt the government should reduce the deficit or increase the deficit, or if the individual had no opinion. The sample results of the study by gender are reported to below.
Gender | Reduce the Deficit | Increase the Deficit | No Opinion |
Female | 224 | 194 | 68 |
Male | 305 | 114 | 25 |
At the .05 significance level, is it reasonable to conclude that gender is independent of a person’s position on the deficit?
Solution:
Here, we have to use chi square test for independence of two categorical variables.
Null hypothesis: H0: The gender is independent of a person’s position on the deficit.
Alternative hypothesis: Ha: The gender is dependent of a person’s position on the deficit.
We are given level of significance = α = 0.05
Test statistic formula is given as below:
Chi square = ∑[(O – E)^2/E]
Where, O is observed frequencies and E is expected frequencies.
E = row total * column total / Grand total
We are given
Number of rows = r = 2
Number of columns = c = 3
Degrees of freedom = df = (r – 1)*(c – 1) = 1*2 = 2
α = 0.05
Critical value = 5.991465
(by using Chi square table or excel)
[Excel command: =CHIINV(0.05, 2)]
Calculation tables for test statistic are given as below:
Observed Frequencies |
||||
Column variable |
||||
Gender |
Reduce the Deficit |
Increase the Deficit |
No Opinion |
Total |
Female |
224 |
194 |
68 |
486 |
Male |
305 |
114 |
25 |
444 |
Total |
529 |
308 |
93 |
930 |
Expected Frequencies |
||||
Column variable |
||||
Gender |
Reduce the Deficit |
Increase the Deficit |
No Opinion |
Total |
Female |
276.4452 |
160.9548 |
48.6 |
486 |
Male |
252.5548 |
147.0452 |
44.4 |
444 |
Total |
529 |
308 |
93 |
930 |
Calculations |
||
(O - E) |
||
-52.4452 |
33.04516 |
19.4 |
52.44516 |
-33.0452 |
-19.4 |
(O - E)^2/E |
||
9.949514 |
6.784404 |
7.744033 |
10.89068 |
7.426172 |
8.476577 |
Chi square = ∑[(O – E)^2/E] = 51.27138
P-value = 0.0000
(By using Chi square table or excel)
[Excel command: =CHIDIST(51.27138, 2)]
P-value < α = 0.05
So, we reject the null hypothesis
There is not sufficient evidence to conclude that the gender is independent of a person’s position on the deficit.