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

Question

Quizplus · Accepted Answer

The 90% confidence interval is calculated using the formula: mean ± (t-value * (standard deviation/√n)). With a sample size of 8, the t-value is approximately 1.895. The interval is 3.125 ± (1.895 * (2.911/√8)), which results in (1.175, 5.075).

An Agricultural Company Wanted to Know If a New Insecticide