Consider the regression model fit to the nisin extraction data in Exercise 12-18.

(a) Calculate 95% confidence intervals on each regression coefficient.

(b) Calculate a 95% confidence interval on mean nisin extraction when x₁ = 15.5 and x₂ = 16.

(c) Calculate a prediction interval on nisin extraction for the same values of the regressors used in part (b).

(d) Comment on the effect of a small sample size to the widths of these intervals.

Transcribed Image Text:

y X2 62.8739 13 11 76.1328 15 11 13 13 87.4667 102.3236 15 13 14 12 76.1872 77.5287 14 12 76.7824 14 12 14 12 77.4381 14 12 78.7417