A recent 10-year study conducted by a research team at theMedical School was conducted to assess how age, blood pressure, andsmoking relate to the risk of strokes. Assume that the followingdata are from a portion of this study. Risk is interpreted as theprobability (times 100) that the patient will have a stroke overthe next 10-year period. For the smoking variable, define a dummyvariable with 1 indicating a smoker and 0 indicating anonsmoker.
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 |
| (a) | Develop an estimated multiple regression equation that relatesrisk of a stroke to the person's age, blood pressure, and whetherthe person is a smoker. |
| Let x1 represent the person's age. |
| Let x2 represent the person's bloodpressure. |
| Let x3 represent whether the person is asmoker. |
| (b) | Is smoking a significant factor in the risk of a stroke?Explain. Use a 0.05 level of significance. |
| (c) | What is the probability of a stroke over the next 10 years forArt Speen, a 65-year-old smoker who has a blood pressure of174? |
| If required, round your answer to two decimal places. |
What action might the physician recommend for this patient?
| What other factors could be included in the model asindependent variables? |
| | (i) | Family History of Stroke | | (ii) | Weight/obesity | | (iii) | Gender | | (iv) | All of the above |
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