In 2017, Mmericans spent a record-high $9.1 billion on Halloween-related purchases (the balance website). Sample data showing the ainourit, in dellars, 16 adiats spent on s Halloween costume are as follows. a. Whot is the estimate of the population mean amount adutts spend on a Halloween costume (t02 decicialy)? b. What is the sample standatd deviation (to 2 decimals)? c. Previde a 95% confidence interval estimate of the population standard deviaticn for the anount adults spend on a Halloween costume (to 2 decamalo). Use Tatis tit it $