A researcher wishes to estimate with 99 confidence the population proportion of likely U S voters who think Congress is doing a good or excellent job Her estimate must be accurate within 2 of the true proportion a No preliminary estimate is available Find the minimum sample size needed b Find the minimum sample size needed using a prior study that found that 44 of the respondents said they thin Congress is doing a good or excellent job c Compare the results from parts a and b a What is the minimum sample size needed assuming that no prior information is available Round up to the nearest whole number as needed n