In 2015, as part of its 10th high school reunion, the class of 2005 held a reception at the high school. In an informal survey, the principal of the high school asked 50 of the attendees about their income. The principal computed the mean income of the 50 attendees to be $148,535. In an article published by the local newspaper, the principal was quoted as stating, "The members of our class of 2005 enjoyed resounding success. Last year, they had a mean income of $148,535!"
Part A: What is a statistical advantage of using the median of the reported incomes, rather than the mean, as the estimate of the typical income? (4 points)
Part B: The principal felt the individuals who attended the reception may be different from the class as a whole. A more detailed survey of the class was planned to determine a better estimate of income. The staff developed two methods based on the available funds to carry out the survey.
Method 1: Send out an e-mail to all 2,476 members of the class and ask them to complete an online form. The staff estimates that at least 500 members will respond.
Method 2: Select a simple random sample of members of the class and contact the selected members directly by phone. Follow up to ensure all responses are obtained. Because method 2 requires more time than method 1, the staff estimates only 100 members of the class can be contacted using method 2.
Which of the two methods would you select for estimating the average yearly income of all 2,476 members of the class of 2005? Explain your reasoning by comparing the two methods and by describing the effect of each method on the estimate.