1. The sample size necessary for a 90% confidence interval to keep the maximum error to within 1/2 of a standard deviation, sigma is known but not given ______ samples
2. The sample size necessary for a 98% confidence interval within 0.02 for a proportion which has a prior population proportion estimate of 0.32 ____ samples
3. The sample size necessary for a 98% confidence interval within 0.02 for a proportion with NO prior population proportion estimate ____ samples