99% confidence interval is mean +/- 2.58 standard deviation/root n where n is sample size. So here we want 2.58x1500/root n to equal 200.
Does anybody know how to do this problem?
A study of elephants is conducted to determine the average weight of a certain subspecies of elephants. The standard deviation for the population is 1500 pounds. At a 99% level, how many elephants need to be weighed so the average weight will be accurate to within 200 pounds?