16. Selenium, again Refer to Exercise 11 in Section 8.4.

You want to compare the daily adult intake of the trace element selenium in two different regions of the United States and you want your estimate to be correct to within 5 micrograms, with probability equal to .90. If you plan to select an equal number of adults from the two regions

(i.e., n 5n 1 2), how large should n1 and n2 be?