Is there a relation between the age difference between husband/wives and the percent of a country that is literate. Researchers found the least-squares regression between age difference (husband age minus wife age), y, and literacy rate (percent of the population that is literate), x, is ŷ = -0.0527x + 7.1. The model applied for 18 ≤ x ≤ 100.
(a) Interpret the slope.
(b) Does it make sense to interpret the y-intercept? Explain.
(c) Predict the age difference between husband/wife in a country where the literacy rate is 25 percent.
(d) Would it make sense to use this model to predict the age difference between husband/wife in a country where the literacy rate is 10 percent? Explain.
(e) The literacy rate in the United States is 99 percent and the age difference between husbands and wives is 2 years. Is this age difference above or below the average age difference among all countries whose literacy rate is 99 percent?