In: Statistics and Probability
Is there a relationship between handedness and gender? A researcher collected the following data in hopes of discovering if handedness and gender are independent (Ambidextrous individuals were excluded from the study). Use the Chi-Square test for independence to explore this at a level of significance of 0.05.
Left-Handed
Right-Handed
Men
13
22
Women
27
18
Solution:-
State the hypotheses. The first step is to state the null hypothesis and an alternative hypothesis.
H0: Handedness and gender are independent.
Ha: Handedness and gender are not independent.
Formulate an analysis plan. For this analysis, the significance level is 0.05. Using sample data, we will conduct a chi-square test for independence.
Analyze sample data. Applying the chi-square test for independence to sample data, we compute the degrees of freedom, the expected frequency counts, and the chi-square test statistic. Based on the chi-square statistic and the degrees of freedom, we determine the P-value.
DF = (r - 1) * (c - 1) = (2 - 1) * (2 - 1)
D.F = 1
Er,c = (nr * nc) / n
Χ2 = Σ [ (Or,c - Er,c)2
/ Er,c ]
Χ2 = 4.114
where DF is the degrees of freedom.
The P-value is the probability that a chi-square statistic having 1 degrees of freedom is more extreme than 4.114.
We use the Chi-Square Distribution Calculator to find P(Χ2 > 4.114) = 0.0425
Interpret results. Since the P-value (0.0425) is less than the significance level (0.05), we cannot accept the null hypothesis.
Thus, we conclude that there is a relationship between Handedness and gender.