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 0' = Til dollars. You would like to be 90% confident that your estimate is within 3 dollarls] of average spending on the birthday parties. How many moms do you have to sample? Do not round mid-calculation. Try this with your statistics calculator, if you increases the confidence level, the sample size 0 decreases 0 increases If you increases the error bound, the sample size 0 increases 0 decreases