In: Statistics and Probability
Hair color in the United States is known to be 40% blond, 40% brown, and 20% black. Miranda does a study to see if the proportions match, and her survey showed 43 people with blond hair, 32 people with brown hair, and 15 with black hair. Use a chi-square test with a level of significance α=0.05.
The null and alternate hypothesis are:
H0: Proportions match as required.
Ha: Proportions do not match as required.
Observed (Oi) | Expected (Ei) | ||
Blonde | 43 | 0.4(90)=36 | 1.36 |
Brown | 32 | 0.4(90)=36 | 0.44 |
Black | 15 | 0.2(90)=18 | 0.50 |
TOTAL | 90 | 90 | 2.30 |
Test statistic value =
The critical value is given by:
Since the test statistic value is less than the critical value, so we do not have sufficient evidence to reject null hypothesis H0. Thus we can say that the proportions match as required.