Fors?k p? ? beskrive det ugjennomtrengelige

1. Wed Mar 13 we discussed various Ch 5 issues, including tolerance thresholds, squared bias + variance for narrow vs. wide estimation, etc. Next week I intend to finish our discussions of Ch 5 material.

2. Exercises for Wed Mar 20 are as follows. First, for the log-linear expansion model of Exam stk 4160 2009 Exercises 1-2, find the tolerance radius for how much a2 can deviate from zero, as seen from the three-parameter model f(y,xi,sigma,a1). Your answer will depend on a1 and needs to be computed numerically. Display the required threshold(a1) curve. Second, go to the Exam stk 4020 1012 set, Exercise 2, with data (xi, yi) for used cars and their sales value. Fit (i) ordinary linear regression and (ii) the indicated nonlinear regression model to these data, along perhaps with one or two more of your own invention. Compute aic, bic, model-robust aic, and cross validation scores. For each candidate model, estimate the focus parameters t0 and mu described in the exercise, and construct confidence intervals for these.