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ONLY NEED THE ANSWER FOR C)

Extracted text: preparation 1 preparation 30 20 8. 5 14 17 14 11 19 17 17 15 3 19 15 12 12 21 14 18 16 14 13 12 4 13 13 16 14 16 14 18 12 21 15 12 10 17 12


Extracted text: Question 10: We wish to compare the effect of two preparations of a virus on tobacco plants. The study involves 20 plants. For each plant, half a leaf is inoculated with preparation 1 and the other half is inoculated with preparation 2. The number of lesions are measured and denoted as x1 and x2, respectively. The data are found in the file TOBACCO.txt. (a) Is it reasonable to assume that the difference of both measurements is normally dis- tributed? (Hint: Produce a quantile-quantile plot (or normal probability plot) for the differences.) (b) Do the preparations have a different effect on the tobacco plants? Justify your answer using a test of hypothesis of Ho : µp = 0 against H1 : µp 7 0, where D is the difference between the number of lesions when preparation 1 and the number of lesions when preparation 2 is used. Use a level of significance of a = = 1%. (c) Give a 95% confidence interval for up. Using this interval, write 1 or 2 sentences compare the mean effect of the two preparations.