You are looking for a job as a salesperson. There are two companies that come into your mind, company A and B. You want to know the payment structure of the two companies, that is how the income of an employer is related to the number of items he or she sells each month. However, such information is not disclosed. You hacked into the systems of the companies and acquired some data about the employee's income (Y) and number of items sold (X) and decide to use your knowledge learned from this course to find out the relationship. a. Write out the true model assumed for company A and then write down the fitted model. What is the sample size? b. Find a 95% confidence interval for the starting salary (the income when no item is sold) in company A. c. What is the proportion of variation explained by the fitted model for company A? d. You estimate you will only be able to sell 100 items each month. Which company do you think can provide you a higher salary?