Hi Ryan,
the homework is going pretty well, and I have one minor question: When we
are working with Z ~ N(0,1), and are asked things like Pr(|Z|>c), I just
calculate the Pr(Z>c) and multipy by 2, relying on the symmetry of
the normal distribution along either side of the y-axis. I am assuming
this gives me a correct answer, but would there be a way to actually work
with |Z| in R?
The symmetry of the normal curve allows exactly the sort of assumption
you've made. Note that for a different member of the Normal family, like
N(4,1), the symmetry would not be around the y-axis, but x=4.
R does not seem to want to let me type pnorm(|1|,
lower.tail=FALSE). Is
there something else I should try?
The R function "abs(x)" returns the absolute value of x. Feel free to use
it if you like.
Cheers,
Ryan