Reconsider the previous two exercises. A 95% confidence interval for the population mean difference in ages (husband–wife, in years) turns out to be (0.92, 2.92). For each of the following, indicate whether the conclusion is valid or invalid:
a. We are 95% confident that at least 92% of husbands are older than their wives.
b. 95% of all husbands are between 0.92 and 2.92 years older than their wives.
c. For about 95 of the 100 married couples in this sample, the husband is between 0.92 and 2.92 years older than his wife.
d. We are 95% confident that the average difference in ages in the population is between 0.92 and 2.92 years.