As the carbon content in steel increases, its ductility tends to decrease. A res
ID: 3158531 • Letter: A
Question
As the carbon content in steel increases, its ductility tends to decrease. A researcher at a steel company measures carbon content and ductility for a sample of 15 types of steel. Based on these data he obtained the following regression results.
The regression equation is:
Ductility = 7.67 - 3.30 Carbon Content
Predictor Coef SE Coef T P
Constant 7.671 1.507 5.09 0.000
Carbon Content -3.296 1.097 -3.01 0.010
S = 2.36317 R-Sq = 41.0% R-Sq (adj) = 36.5%
Answer the following questions:
a) What is the 95% confidence interval for the slope of the regression equation?
b) Do you think the Least Square Estimate resulted to a good fit model?
c) If it is not what do the researcher do to get a good fit linear regression Model?
Explanation / Answer
a) What is the 95% confidence interval for the slope of the regression equation?
B1 +/- SE coef
-3.296 +/- 1.097
-4.393 < B1 < -2.199
b)
b) Do you think the Least Square Estimate resulted to a good fit model?
no because , you need at least 50% in R squared
c)
the reaseacher need to do see what outliers are in the regression model , and take out the values outliers and do other regression
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.