Determine the sample size necessary to estimate

Determine the sample size necessary to estimate a population proportion to within .03 with 90% confidence assuming you have no knowledge of the approximate value of the sample proportion Determine the sample size necessary to estimate a population proportion to within .03 with 90% confidence assuming you have no knowledge of the approximate value of the sample proportion

Suppose the Probability that a part fails is 0.1.

Suppose the Probability that a part fails is 0.1. Our question involves computing the probability that out of 500 parts selected, What is P(more than 35 are defective)? We are going to use the Normal Distribution to approximate this probability.
Question: Since we are calculating the probability of more than 35, we would actually start at what value to begin converting to a standardized Zscore in order to accommodate the histogram bars of the binomial?