Confidence intervals (sample size

MyOpenMath You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately 72%. You would like to be 95% confident that your estimate is within 2.5% of the true population proportion. How large of a sample size is required? Hint: Video [+] n = 0/1 pt 9 3 99 You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately o = 49.9. You would like to be 9% confident that your estimate is within 1.5 of the true population mean. How large of a sample size is required? Hint: Video [+] n = Question 7 0/1 pt 9 3 9 You want to obtain a sample to estimate how much parents spend on their kids birthday parties. Based on previous study, you believe the population standard deviation is approximately o = 34.5 dollars. You would like to be 99% confident that your estimate is within 10 dollar(s) of average spending on the birthday parties. How many parents do you have to sample? Hint: Video [+] n =