In a study conducted at the Virginia Polytechnic Institute a

  In a study conducted at the Virginia Polytechnic Institute and State University on the development of ectomycorrhizal. Ectomycorrhizal is a symbiotic relationship between the roots of trees and a fungus in which minerals are transferred from the fungus to the trees and sugars from the trees to the fungus. In this study 20 northern red oak seedlings with the fungus Pisolithus tinctorus were grown in a greenhouse. All seedlings were planted in the same type of soil and received the same amount of sunshine and water. Half received no nitrogen at planting time to serve as a control and the other half received 368 ppm of nitrogen in the form NaNO₃. The stem weights recorded in grams, at the end of 140 days are given in the file HW17_Seedlings.xlsx  In a study conducted at the Virginia Polytechnic Institute and State University on the development of ectomycorrhizal. Ectomycorrhizal is a symbiotic relationship between the roots of trees and a fungus in which minerals are transferred from the fungus to the trees and sugars from the trees to the fungus. In this study 20 northern red oak seedlings with the fungus Pisolithus tinctorus were grown in a greenhouse. All seedlings were planted in the same type of soil and received the same amount of sunshine and water. Half received no nitrogen at planting time to serve as a control and the other half received 368 ppm of nitrogen in the form NaNO₃. The stem weights recorded in grams, at the end of 140 days are given in the file HW17_Seedlings.xlsx

0.46

Conduct a hypothesis test at the a=0.05 level of significance to determine if the stem weight of seedlings that receive nitrogen at planting is greater than stem weight of seedlings that do not receive nitrogen at planting. Assume population variances are not equal.

Calculate the corresponding confidence bound for the hypothesis test above. Briefly explain what it is telling you in terms of the stem weights in the different groups.

Solution