A person was modeling a declining population with a decay factor of 0.5 using pennies. They started with 100 pennies and flipped all 100 pennies. Any pennies that landed on tails were removed. Then, the remaining pennies are flipped again and again the ones landing on tails were removed. The process is repeated until no pennies are left. How many flips is the most reasonable expectation for when this model should reach 0 pennies? 4 flips

8 flips

12 flips

16 flips

Arandom sample of 15 observations is used to estimate the population mean. the sample mean and the standard deviation are calculated as 172 and 63, respectively. assume that the population is normally distributed. a. with 99 confidence, what is the margin of error for the estimation of the population mean? b. construct the 99% confidence interval for the population mean. c. construct the 95% confidence interval for the population mean. d. construct the 83% confidence interval for the population mean. hint: you need to use excel function =t.inv.2t to find the value of t for the interval calculation.