An extrusion die is used to produce aluminum rods. Specifications are given for the
length and the diameter of the rods. For each rod, the length is classified as too short,
too long, or OK, and the diameter is classified as too thin, too thick, or OK. In a
population of 1000 rods, the number of rods in each class is as follows:
Diameter
Length
Too Thin
OK
Too Thick
Too Short
10
3
5
OK
38
900
4
Too Long
2
25
13
a- A rod is sampled at random from this population.
What is the probability that it is too short?
b- If a rod is sampled at random, what is the probability
that it is either too short or too thick?