Although Germany has one of the healthiest economies in the euro zone, it has one of the lowest homeownership rates in Europe, and the homeownership rates in Germany have been declining since 2012. According to Eurostat, the German homeownership rate was 51.7% in 2017 (compared to 63.9% in the United States). Suppose, from a random sample of 270 households in Germany in 2018, 117 were occupied by the owners of the residence.

a. Construct a 98% confidence interval to estimate the actual proportion of households in Germany that are occupied by their owners in 2018.

b. What is the margin of error for this sample?

c. Is there evidence that this proportion has changed since 2017 based on this sample?