Chapter 8 T951.- 1hr33mins X Score: 7.7!19 9X19 answered Progress saved Done E] WC. 0 Question 12 v El\" 0J1 pt '0 2 6) Details 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 a = 73.7 dollars. You would like to be 95% confident that your estimate is within 10 dollar(s) of average spending on the birthday parties. How many parents do you have to sample