written 5.6 years ago by | modified 2.6 years ago by |
Justify if there is any relationship between sex and color for the following data:
Color | Male | Female |
---|---|---|
Red | 10 | 40 |
White | 70 | 30 |
Green | 30 | 20 |
written 5.6 years ago by | modified 2.6 years ago by |
Justify if there is any relationship between sex and color for the following data:
Color | Male | Female |
---|---|---|
Red | 10 | 40 |
White | 70 | 30 |
Green | 30 | 20 |
written 5.6 years ago by |
Solution:
Color | Male | Female | Total |
---|---|---|---|
Red | 10 | 40 | 50 |
White | 70 | 30 | 100 |
Green | 30 | 20 | 50 |
Total | 110 | 90 | 200 |
Step 1: Null Hypothesis $(H_{0}) \Longrightarrow$ There is no relationship between sex and color.
Alternative Hypothesis $(H_{a}) \Longrightarrow$ There is relationship between sex and color.
Step 2: Calculation of test statistic $\Longrightarrow$ On the basis of this hypothesis, the number in the first cell $=\cfrac{A \times B}{N}$
where, A = Number of male in the first column
B = Number of Red color
N = Total number of observation
The number in the first cell$=\cfrac{110 \times 50}{200}=27.5 \approx28$
Similarly fill the table,
Expected frequency table,
Color | Male | Female | Total |
---|---|---|---|
Red | $\cfrac{110 \times 50}{200} = 27.5 \approx 28$ | 50-28=22 (Total-Male) | 50 |
White | $\cfrac{110 \times 100}{200} = 55$ | 100-55=45 (Total-Male) | 100 |
Green | 110-28-55 | 90-22-45=23 | 50 |
Total | 110 | 90 | 200 |
Calculation of $\cfrac{(O-E)^{2}}{E}$
Observed Frequency (O) | Expected Frequency (E) | $(O-E)^{2}$ | $x^{2}=\cfrac{(O-E)^{2}}{E}$ |
---|---|---|---|
10 | 28 | 324 | 11.5714 |
40 | 22 | 324 | 14.7273 |
70 | 55 | 225 | 4.0909 |
30 | 45 | 225 | 5 |
30 | 27 | 9 | 0.3333 |
20 | 23 | 9 | 0.3913 |
Total | $x^{2}=36.1142$ |
Step 3: Level of significance (LOS)
$LOS=0.05=\alpha$
Degree of freedom=(r-1)(c-1)=(2-1)(3-1)=2
Step 4: Critical Value $\Longrightarrow$ For 2 degrees of freedom and 5% level of significance, the table value of $(X_{a}^{2})=5.991$
Step 5: Decision $\Longrightarrow$
Since the calculated value of $x^{2}=36.1142$ is greater than the table value of $X_{a}^{2}=5.991$.
$\therefore$ The null hypothesis is rejected.
$\therefore$ There is relationship between sex and color.