Private colleges and universities rely upon money contributed by individuals and corporations for their operating expenses. Much of this money is invested in fund called an endowment, and college spends only the interest earned by the fund. A current survey of eight private colleges in United States revealed the following endowments (in millions of dollars): 81.8, 75.5, 245.7, 499.9, 116.1, 156.3, 107.3, and 211.9. What value will be used as the point estimate for the mean endowment of all private colleges in the United States?