7.4. When a recent Eurobarometer survey asked subjectsin each European Union country whetherthey would be willing to pay more for energy produced from renewable sources than for energy produced from other sources, the proportion answering yes varied from a high of 0.52 in Denmark (« = 1008)

to a low of 0.14 in Lithuania (n = 1002). For this survey:

(a) Estimate the difference between Denmark and Lithuania in the population proportion ofyes responses.

(b) From the se = 1 — Tr)/n formula in Chapter 5, the proportion estimates have se = 0.0157 for Denmark and se = 0.110 for Lithuania. Use these to find the se for the difference estimate in (a). Interpret this se.