Posted: January 7th, 2016

Identify the response and the explanatory variables with proper reasoning

PLEASE ANSWER QUESTIONS FROM (a) to (f) PLEASE USE R STATISTICAL SOFTWARE TO ANSWER ALL QUESTIONS. NO MANUAL CALCULATION ANYWHERE. INCLUDE ALL THE NECESSARY CODES INCLUDE ONLY THE RELEVANT OUTPUTS FROM THE SOFTWARE. ALL PLOTS SHOULD BE PROPERLY LABELLED. (X-AXIS, Y-AXIS, TITLE, ETC.). PLEASE GIVE PROPER EXPLANATION FOR THE STEPS AND CONCLUSIONS WHEREVER APPLICABLE Anti-Anginal Response against Disease History Treadmill stress tests were applied to patients with angina pectoris before and 4 weeks after once-daily dosing with an experimental anti-anginal medication. The main objective for carrying out this study is to check if the improvement in exercise duration is dependent on the patient’s disease history. This data file represents the disease duration time (in years) since initial diagnosis and percent-improvement in treadmill walking times. QUESTIONS : (a) Identify the response and the explanatory variables with proper reasoning

(b)  Check graphically if the dependency between “improvement” and “disease duration time” can be considered to be linear. (c)  Now, use a formal test of hypothesis to check for the linear relationship in part (b) and draw appropriate conclusion (d)  How does the disease duration effect the percentage improvement in exercise duration (e)  What assumption did you make to carry out the testing in part (c). Is there any other assumptions required to formulate a linear model for “improvement” and “disease duration time” (f)  Check all the model assumptions made in part (d) graphically and comment on the violation or non violation of the model assumptions with proper reasoning

Patient_number Disease_duration Improvement 1 1 40 2 1 90 3 3 30 4 2 30 5 1 80 6 5 60 7 1 10 8 4 -10 9 2 50 10 6 40 11 1 60 12 4 0 13 2 50 14 2 100 15 3 20 16 3 70 17 5 -30 18 3 20 19 1 40 20 6