please help with this question

A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained if he wishes the estimate to be within 3 percentage points with 99% condence if (a) he uses a previous estimate of 22%? (b) he does not use any prior estimates? Click here to view the standard normal distribution table (p_ag); Click here to view the standard normal distribution table (Egg); (a) n = I] (Round up to the nearest integer.) (b) n = D (Round up to the nearest integer.)