exercises for 25-27 September

1. We're rounding off Ch2 and will start Ch3 on 25-27 September.

2. On Mon 25 Sept we carry out the "Nils leaves the room during the break" exercise; Berit and Oskar take notes and speak with Nils a bit later on, about aspects of the course.

3. For 25-27 Sept, first do Story IV. I've placed birthweight-boys and birthweight-girls on the website, read these into your computers. As part of the exercise, make confidence plots for boys and girls, as a function of q from say 0.05 to 0.95, with (i) estimated quantiles and (ii) a 95% band. This involves estimating the variances q(1-q)/f(quantile(q)), for boys and girls. You may use "density" in R (without caring so much about which formulae are under the hood), e.g. using 

fhatBval[j] <- mean( density(yyB,from=QBval[j],to=QBval[j])$y )

fhatGval[j] <- mean( density(yyG,from=QGval[j],to=QGval[j])$y )

(There might be simpler ways, but at least this works.) 

4. After Story IV, we do these, from Ch 3: 1, 2, 6, 7, 8, 9. And then Story III. Rolf does 3.1.