According to a recent pole only 21% of Americans were satisfied with the direction the U.S. is heading. To investigate the reliability of the report an independent polling organization surveyed 500 Americans and inquired as to whether or not they were satisfied with the way things are progressing in the U.S. The response indicated 117 of 500 were satisfied.

Question

According to a recent pole only 21% of Americans were satisfied with the direction the U.S. is heading.  To investigate the reliability of the report an independent polling organization surveyed 500 Americans and inquired as to whether or not they were satisfied with the way things are progressing in the U.S.  The response indicated 117 of 500 were satisfied.
A.  Calculate a 95% confidence interval to estimate the true proportion of Americans who are currently satisfied  with the direction the U.S. is heading .
B.  If in the future the polling organization wanted to conduct a 99% confidence interval  to estimate the true proportion of Americans who are currently satisfied with the direction the U.S. is heading and have the margin of error to be no larger than 3%, how many Americans should be included in the survey.