Question 1. (2 points total. Each part is worth 0.5 points.) Suppose we are interested in understanding the amount of income (in dollars) "the typical person" in the United States makes in a given year. We would like to construct an estimate of the average income of individuals in the United States, so we conduct a random sample of 1,000 people who live in the state of Massachusetts. Let the symbol u stand for the average income in the population and let the symbol u stand for the average income in the sample. Let x be a variable representing income, so that x; denotes the income of the ith person in the sample. a. What does u represent? What does f represent? b. What is the population (N) and what is the sample (n) in this case? c. Describe (in words and in math) how to construct u. d. Are there any other issues with using f to describe the income of "the typical person" in the US? Why or why not? (Hint: Is the mean the best measure of central tendency in this case?)