A music industry researcher wants to estimate, with a 90% confidence level, the proportion of young urban people (ages 21 to 35
years) who go to at least 3 concerts a year. Previous studies show that 21% of those people (21 to 35 year olds) interviewed go to at least 3 concerts a year. The researcher wants to be accurate within 1% of the true proportion. Find the minimum sample size necessary.
My method is on a) you would just subtract 12 and 7 which is 5. You can do the rest and then when you get all the answers put them from smallest to largest
