In 2017, Americans spent a record-high $9.1 bilion on Halloween-related purchases (the balance website). Sample data showing the amount, in doliars, 16 adults spent on a Halloween costume are as follows. a. What is the estimate of the population mean amount adults spend on a Halloween costume (to 2 decimais)? 3 b. What is the sample standard deviation (to 2 decimais)? 3 c. Provide a 95% confidence interval estimate of the population standard deviation for the amount aduits spend on a Halloween costume (to 2 decimals). Use Table 1