ANSWER THIS QUESTION

The le \"folate.txt\" contains data on red cell folate levels (folate) in patients receiving three different methods of ventilation (ventilation) during anesthesia. The three djEerent methods are coded as follows: 1 = 3550% oxygen given continuously for 24 hours 2 = 50% nitrous oxide and 50% oxygen given continuously for 24 hours. 3 = 50% nitrous oxide and 50% oxygen given only during the operation. a. Plot the data, and sunn'narise the information available from the plot. b. Fit a model to compare the folate for different ventilation methods. Produce and inter pret the summary table of coefcients. c. There is one pairwise comparison that cannot be tested explicitly by referring to the table of coefcients. Create a contrast that allows for that comparison. You should also create a second contrast to complete an orthogonal set. (i) State the null hypothesis corresponding to each of these contrasts, in words and using statistical notation. (ii) Verify that the two contrasts form an orthogonal set. (iii) Heron the model by partitioning the SS for ventilation using the two contrasts. Produce and interpret relevant output