In: Statistics and Probability
A researcher wanted to examine if there is a relationship between color preference (i.e., favorite color: red, yellow, green or blue) and personality type (i.e., extrovert or introvert). He selected a sample of n = 200 participants; each participant took a personality test and identified the favorite color. The collected data are shown in the table below.
Do the data indicate a significant relationship between personality type and color preference? Test with p < .01.
RED |
YELLOW |
GREEN |
BLUE |
|
INTROVERT |
10 |
3 |
15 |
22 |
EXTROVERT |
90 |
17 |
25 |
18 |
For full credit include:
#solution:
Hypothesis
Ho:Colour preference and personality type are independent
Hao:Colour preference and personality type are dependent
#observed frequency | ||||||
RED | YELLOW | GREEN | BLUE | Total | ||
INTROVERT | 10 | 3 | 15 | 22 | 50 | |
EXTROVERT | 90 | 17 | 25 | 18 | 150 | |
total | 100 | 20 | 40 | 40 | 200 | |
Expected | Ei=Σ corespondin row*Σcorespondin column/Σtotal | RED | YELLOW | GREEN | BLUE | Total |
INTROVERT | 25 | 5 | 10 | 10 | 50 | |
EXTROVERT | 75 | 15 | 30 | 30 | 150 | |
total | 100 | 20 | 40 | 40 | 200 | |
chi square χ2 | =(Oi-Ei)2/Ei | RED | YELLOW | GREEN | BLUE | Total |
INTROVERT | 9 | 0.8 | 2.5 | 14.4 | 26.7 | |
EXTROVERT | 3 | 0.266666667 | 0.833333333 | 4.8 | 8.9 | |
total | 12 | 1.066666667 | 3.333333333 | 19.2 | 35.6 |
## chi square χ2=sum(=(Oi-Ei)2/Ei)=35.6
df=(r-1)*(c-1)=(2-1)*(4-1)=3
critical value of Chi2=11.35---using Excell==CHIINV(0.01,3)
#test statistics > critical value hence we reject Ho at 1% l.o.s ie 35.6>11.35
#Conclusion:
Colour preference and personality type are dependent.
ie there is relationship between personality type and color preference