An Agricultural Company Wanted to Know If a New Insecticide

An agricultural company wanted to know if a new insecticide would increase corn yields.Eight test plots showed an average increase of 3.125 bushels per acre.The standard deviation of the increases was 2.911 bushels per acre.Determine a 90% confidence interval for the mean increase in yield.

A) (1.175,3.815)
B) (1.175,5.075)
C) (2.435,3.815)
D) (2.435,5.075)
E) (-5.075,-3.815)