Refer to Exercise 12.7. Portions of the MINITAB printout are shown here.
MINITAB output for Exercise 12.40
Regression Analysis: y versus x
The regression equation is
y = 6.00 - 0.557 x

a. Find a 95% confidence interval for the average value of y when x = 2.
b. Find a 95% prediction interval for some value of y to be observed in the future when x = 2.
c. The last line in the third section of the printout indicates a problem with one of the fitted values. What value of x corresponds to the fitted value Å· = 1.5429? What problem has the MINITAB program detected?

Transcribed Image Text:

Predictor Constant Coef 6.0000 -0.55714 SE Coef 0.1759 0.04518 34.10 -12.33 0.000 0.000 Predicted Values for New Observations New obs Fit SE Fit 95 , 0% CI 95 . 0% pl 4.8857 0.1027 (4.6006, 5.1708) (4.2886, 5.4829) 1.5429 0.2174 《0.9392 , 2.1466) (0.7430, 2.3427)x x denotes a point that is an outlier in the predictors. Values of Predictors for New Observations New Obs 1. 2.00 8.00