When a recent Eurobarometer survey asked subjects in each European Union country whether they 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 (n = 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 of yes responses.

(b) From the se =



πˆ (1 − πˆ )/n formula, the proportion estimates have se = 0.0157 for Denmark and se = 0.0110 for Lithuania. Use these to find the se for the difference estimate in (a). Interpret this se.