Asurvey of first-time home buyers found that the mean of annual household income was $50,000 (cnbc, july 11, 2000). assume the survey used a sample of 400 first-time home buyers and assume that the population standard deviation is $20,500. construct a 97% confidence interval for the mean annual household income for first-time home buyers. the margin of error e = $ (to 0 decimals) . if we wish to reduce the margin of error to only $1000 while keeping the confidence level at 97%, what would be the minimum required sample size? n = (enter an integer value)