1. Dr. Dream, an expert in infectious diseases, wanted to estimate the proportion of the adult population in the U.S. that received a flu vaccine. They randomly sample 866 individuals and 388 of them received a flu vaccine. They decide to report a 90% confidence interval for the population proportion.

a. What is the value of the standard error?

b. What is the value of the margin of error?

c. Compute the 90% confidence interval.