Refer to given Exercise. Calculate a 50% confidence interval that estimates the proportion of U.S. adults who think penalties for underage drinking should be more strict.

Exercise
A question in a 2007 Gallup poll asked, "Do you think the penalties for underage drinking should be made more strict, less strict, or remain the same?" The sample proportion that responded "more strict" was .60 (60%). This result will be used to estimate the proportion of all adults in the United States who think that penalties for underage drinking should be more strict. The sample consisted of n = 537 randomly selected adults in the United States (Source: www.pollingreport.com/life.htm).

a. What is the population parameter of interest in this situation?

b. Calculate the standard error of the sample proportion.

c. Calculate a 95% confidence interval that estimates the population proportion who think that penalties for underage drinking should be more strict.

d. Write a sentence that interprets the confidence interval found in part (c).