In: Statistics and Probability
A researcher was curious about whether people’s attitudes are related to their behaviors. As a simple experiment, the researcher measured people’s attitudes and behaviors regarding housework.
On the attitude side, the researcher measured the level of agreement on the statement “It is much better for everyone involved in housework: strongly agree, agree, disagree, and strongly disagree” On the behavioral side, the respondents are asked to estimate how many hours of housework they do per week.
Based on your analysis of the data below, please come up with a conclusion whether people who respond differently to the attitudinal question actually behave differently?
Once you have arrived at an answer to each question, please write a sentence or two interpreting the result (100 pts).
Attitude |
Strongly Agree |
Agree |
Disagree |
Strongly Disagree |
34 |
28 |
40 |
43 |
|
31 |
26 |
42 |
42 |
|
33 |
24 |
39 |
38 |
|
32 |
26 |
32 |
39 |
|
28 |
32 |
41 |
41 |
|
27 |
34 |
39 |
44 |
|
43 |
27 |
43 |
48 |
|
38 |
26 |
44 |
36 |
|
27 |
31 |
41 |
||
31 |
39 |
|||
Sample N |
10 |
9 |
10 |
8 |
Sample Mean |
32.40 |
28.22 |
40.00 |
41.38 |
Sample St.Dev |
5.03 |
3.35 |
3.30 |
3.78 |
c.1. Find the grand mean, the mean of all values in the samples. (10 pts)
c.2. Find the between-group variance. (15 pts)
c3. Find the within group variance.
c.4. Compute the F-value. (15 pts)
Ans a ) the null ad alternative hypothesis is
Ho:u1=u2=u3=u4
Ha: at least one u is different
using excel>data >data analysis>one way anova
we have
SUMMARY | ||||||
Groups | Count | Sum | Average | Variance | ||
Column 1 | 10 | 324 | 32.4 | 25.37778 | ||
Column 2 | 9 | 254 | 28.22222 | 11.19444 | ||
Column 3 | 10 | 400 | 40 | 10.88889 | ||
Column 4 | 8 | 331 | 41.375 | 14.26786 | ||
grand mean | 35.499 | |||||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Between Groups | 1050.872 | 3 | 350.2907 | 22.40967 | 4.26E-08 | 2.891564 |
Within Groups | 515.8306 | 33 | 15.63123 | |||
Total | 1566.703 | 36 |
Ans b ) the critical value from the F test distribution is 2.892
c.1.the grand mean, the mean of all values in the samples. is 35.499
c.2 the between-group variance from table is 350.2907
c3 the within-group variance from table is 15.631
c.4. the F-value = 22.41