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tell me how to do this wihtout excel and calculator. A 10-year study conducted b

ID: 3227605 • Letter: T

Question

tell me how to do this wihtout excel and calculator.

A 10-year study conducted by the American Heart Association provided data on how age, blood pressure, and smoking relate to the risk of strokes. Risk is interpreted as the probability that the patient will have a stroke over the next 10-year period. For the smoking variable, a dummy variable is defined as 1 for smokers and 0 for non-smokers. Age and blood pressure are both continuous variables. The following Minitab output is given:

Analysis of Variance

Source      DF Adj SS   Adj MS F-Value P-Value

Regression   3 3660.7 1220.25    36.82    0.000

Age        1 1394.8 1394.84    42.09    0.000

Pressure   1 1027.4 1027.35    31.00    0.000

Smoker     1   281.1   281.10     8.48    0.010

Error       16   530.2    33.14

Total       19 4190.9

Model Summary

      S  

5.75657

Coefficients

Term        Coef SE Coef T-Value P-Value

Constant   -91.8     15.2    -6.03    0.000

Age        1.077    0.166     6.49    0.000

Pressure 0.2518 0.0452     5.57    0.000

Smoker    8.74     3.00     2.91    0.010

a. Write the regression equation.

b. Interpret all the coefficients.

c. Are coefficients statistically significant? Explain.

d. Find adjusted-R2 and explain what it means.

e. What is the risk of stroke for an individual who smokes at age 60 with blood pressure 150?

Explanation / Answer

Answer to the questions below:

a.Y = -91.8+1.077*Age +.2518*Pressure +8.74*Smoker

b.

1 unit increase in age casuses prediction to rise by 1.077
1 unit increase in Pressure casuses prediction to rise by .2518
1 unit increase in Smoker casuses prediction to rise by 8.74

c.

Yes they are . See the p-value, every one of them is less than .05, hence all
are significant

d.

R2 square is (4190-530.2)/4190

= 87.3%

e.
= -91.8+1.077*60 +.2518*150+8.74*1 = 19.33