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 σ
=
80.4
dollars. You would like to be 90% confident that your estimate is within 5 dollar(s) of average spending on the birthday parties. How many moms do you have to sample? Do not round mid-calculation.

n =

Try this with your statistics calculator, if you increases the confidence level, the sample size
decreases
increases

If you decreases the error bound, the sample size
increases
decreases