B. component Use R instead of a calculator for Question 7. Please attach the B. commands, output and graphs that you used to answer the question. The R output alone is not an answer to the question. Please write a sentence or two to properly answer each question. . In a stud}r conducted at Virginia Tech on the development of ectoniycorrhizal, a sym- biotic relationship between 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, 20 northern red oak seedlings exposed to the fungus Pisolthus tinctor'us 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 served as a control, and the other half received 368 ppm of nitrogen in the form N (IN 03 The stem weights, in grams, at the end of 140 days were recorded and were saved in variables 3:1 (control) and 3:2 (nitrogen), by the R code given below: x1=c(0.42, 0.24, 0.41, 0.34, 0.23, 0.28, 0.37, 0.42, 0.33, 0.38) x2=c(0.55, 0.80, 0.61, 0.58, 0.48, 0.53, 0.67, 0.71, 0.49, 0.59) (a) Produce overlayed quantilequantile plots for the two groups of stem weights and produce comparative boxplots for the two groups of stem weights. Is it reasonable to assume that the stern weights are normally distributed? Is it reasonable to assume that the variances of the stem weights are the same for the groups? (13) Can we say that the use of nitrogen produces higher stem weights on average? (Use or = 0.01.) (c) Give a 97% condence interval for the diHerence {1.1 Jug, where n, is the mean stern weight without nitrogen and n2 is the mean stem weight with nitrogen