Assume that an ecologist is studying the effects of the insecticide DDT on wild birds in Sumatra. DDT sprayed on insects and vegetation subsequently eaten by female birds seems to affect the thickness of their eggshells and thus affects the protection of the embryonic birds. Assume the ecologist knows that the mean eggshell thickness is untreated birds (birds that have not eaten matter sprayed with DDT) is 330 microns and the variance is 2500 microns squared. Assume also that the thickness follow a normal distribution. The ecologist takes a sample of 16 eggshells and finds a sample mean of 290. The ecologist is interested in seeing if the spraying of DDT has any effect on the eggshells. (Alpha = .05)
How do you know which hypothesis test to use ? T or Z ?
B) Test Statistic
E) Construct a 99% C.I. for the mean
A Complete, Neat and Step-by-step Solution is provided in the attached files.