The following 5 questions are based on this information. An economist reports that 47% (p¯=0.47p¯=0.47) of a random sample of 1200 middle-income American households actively participate in the stock market. The goal is to construct a 95% confidence interval of the proportion (pp) of all middle-income Americans who actively participate in the stock market. The standard error (SE) of p¯p¯ is Select one:

a. 0.47
b. 0.047
c. 0.021
d. 0.014