The Reviews editor for a certain scientific journal decides whether the review
for any particular book should be short (1–2 pages), medium (3–4 pages), or long
(5–6 pages). Data on recent reviews indicates that 45% of them are short, 35%
are medium, and the other 20% are long. Reviews are submitted in either Word
or LaTeX. For short reviews, 70% are in Word, whereas 55% of medium reviews
are in Word and 40% of long reviews are in Word. Suppose a recent review is
randomly selected.
(a) What is the probability that the selected review was submitted in LaTeX for-
mat?
(b) If the selected review was submitted in Word format, what are the posterior
probabilities of it being short, medium, or long?