An Agricultural Company Wants to Know If a New Insecticide

Multiple Choice

An agricultural company wants to know if a new insecticide would increase corn yields.They will use test plots to collect observations with and without the insecticide.If they want to estimate the mean increase with a margin of error of 1.2 bushels per acre,with 95% confidence,estimate the minimum number of test plots they need.A previous study showed that the standard deviation of the increases was about 2.9 bushels per acre.

A) 23
B) 16
C) 8
D) 63
E) 39