The National Occupant Protection Use Survey (NOPUS) was conducted to provide probability-based data on motorcycle helmet use in the United States. The survey was conducted by sending observers to randomly selected roadway sites where they collected data on motorcycle helmet use, including the number of motorcyclists wearing a Department of Transportation (DOT)-compliant helmet (National Highway Traffic Safety Administration website, January 7, 2010). Sample data consistent with the most recent NOPUS are shown below. Answer questions 8 -10. Type of Helmet Region DOT-Compliant Noncompliant Northeast 96 62 Midwest 86 43 South 92 49 West 76 16 Total 350 170 (Hint: The above table is a cross-tabulation, but the right margin is missing. You will need to calculate the total number of motorcyclists for each region as well as the total number of motorcyclists of all four regions.) 1. What is the probability of DOT-compliant helmet use by region of the country? What region has the highest probability of DOT-compliant helmet use? (Hint: Please pay attention that the question asks about the probability of DOT-compliant helmet use in each region of the country. You need to divide the number of motorcyclists wearing a DOT-compliant helmet in each region by the total number of motorcyclists of the region to calculate the probability.) 2. Simple random sampling uses a sample of size n from a population of size N to obtain data that can be used to make inferences about the characteristics of a population. Suppose that, from a population of 50 bank accounts, we want to take a random sample of four accounts in order to learn about the population. How many different random samples of four accounts are possible? (Hint: Is this question about permutation or combination?)