Ch 8 HW: Confidence Intervals Progre Score: 21/28 9/12 answered Question 12 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 = 32.5 dollars. You would like to be 9% confident that your estimate is within 2 dollar(s) of average spending on the birthday parties. How many parents do you have to sample? n = Question Help: DVideo B Written Example Message instructor Submit Question Jump to