1. In your own words explain the difference between a point estimate and an interval estimate of a parameter? Which is better? Why? 

2. What information is necessary to calculate a confidence interval? Is the size of the population relevant when one is determining the sample size for a confidence interval? What is necessary to determine the sample size? 

3. A researcher is interested in estimating the noise levels in decibels at area urban hospitals.  He wants to be 90% confident that his estimate is correct.  If the standard deviation is 4.8, how large a sample is needed to get the desired information and to be accurate within 0.65 decibels?