Problem 7-19 A recent 10-year study conducted by a research team at the Medical
ID: 2921565 • Letter: P
Question
Problem 7-19
A recent 10-year study conducted by a research team at the Medical School was conducted to assess how age, blood pressure, and smoking relate to the risk of strokes. Assume that the following data are from a portion of this study. Risk is interpreted as the probability (times 100) that the patient will have a stroke over the next 10-year period. For the smoking variable, define a dummy variable with 1 indicating a smoker and 0 indicating a nonsmoker.
Option (iv)
Risk
Age Blood
Pressure
Smoker 12 57 150 No 26 60 165 No 11 59 155 No 57 86 170 Yes 28 59 196 Yes 50 76 189 Yes 17 56 155 Yes 32 78 120 No 37 80 135 No 15 78 98 No 22 71 152 No 36 70 173 Yes 15 67 135 Yes 48 77 209 Yes 14 60 199 No 36 82 119 Yes 8 65 166 No 34 82 125 No 3 61 117 No 39 60 208 Yes
Explanation / Answer
a)
Y = -97.1987+1.209*X1+0.2369*X2+7.4400*X3
b)
P - value of X3 is less than 0.05. So smoking is significant factor
c)
Y = -97.1987 + 1.209* 65+0.2369*167+7.440*1 = 28.39
d)
P- values of all the variables are less than 0.05. So all are significant factors.
So option IV is correct
Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0% Intercept -97.1987 16.5527 -5.87207 2.36E-05 -132.289 -62.1085 -132.289 -62.1085 X1 1.209524 0.165706 7.299224 1.78E-06 0.858244 1.560805 0.858244 1.560805 X2 0.236936 0.056232 4.213515 0.00066 0.117729 0.356143 0.117729 0.356143 X3 7.440082 3.413219 2.179785 0.044557 0.204381 14.67578 0.204381 14.67578