Answer all questions with explanation

Based on surveys, the average trick-or-treater in 2021 collected 90 pieces of candy, with a standard deviation of 15 pieces. If we sample trick-or-treaters in groups of 10 and average together their candy counts, what would we expect the standard deviation of those averages to be? (Express your answer with 2 decimal places.) Answer If we increase the number of trick-or-treaters we average together from 10 at a time to 20 at a time, what would the new standard deviation of the averages be? (Express your answer with 2 decimal places.) Answer: How big of a sample of trick-or-treaters would we need, for the standard error to be 2.5? (Express your answer as an integer.) Answer: How big of a sample of trick-or-treaters would we need, for the standard error to be 1? (Express your answer as an integer.) Answer: Assume that the standard error for sampling trick-or-treater candy counts is 2. What is the probability that you get an average candy count of less than 94 pieces? (Express your answer to 2 decimal places.)