Answer :
Final answer:
The null hypothesis for the IQ study posits no difference between husbands' and wives' average IQ, while the alternative hypothesis suggests a difference. When studying marital satisfaction and childcare responsibilities, the null hypothesis would indicate no difference in satisfaction levels, with the alternative hypothesis positing that husbands are more satisfied.
Explanation:
In the study regarding the average IQ difference between husbands and wives, the null and alternative hypotheses are critical components of hypothesis testing. The null hypothesis (H0) posits that there is no difference between the means of the two groups - in this case, the average IQ of husbands is the same as that of wives. Conversely, the alternative hypothesis (H1) suggests that there is a difference - meaning the average IQs are not the same between husbands and wives.
For a study looking at whether husbands are more satisfied with the division of childcare responsibilities than their wives, the null hypothesis might state that there is no mean difference in satisfaction levels (H0: μd = 0, where μd represents the mean difference in satisfaction levels). The alternative hypothesis would be that the mean difference is negative, indicating husbands are more satisfied (H1: μd < 0).
In conclusion, the null hypothesis serves as a statement of 'no effect' or 'no difference,' while the alternative hypothesis represents what the researcher is trying to demonstrate, whether it be a positive, negative, or just a plain difference.
