2. According to the United States Census Bureau, 15.5% of the LLB. population in El 1was aged I55 years or older.1 A marketing researcher contacts 5|] people in the US. at random. Answer the following questions. Use Excel or the standard normal tables. {a} How many people1 out of this sample of 51], do you expect to be aged 55 or older?I Why? {b} What is the probability that at least ten out of the 5!] people whom the researcher contacts are aged 55 years or older? What is the probability that at most two of them are 55 or older? Please explain. {c} Maire a rough sketch of the graph of the probability density function that you used to answer Question 2b. What are the mean and stande deviation of the resulting distribution? Discuss why it might be reasonable to use this distribution to obtain your answers to Question 2b