Question

Dogs are inbred for such desirable characteristics as blue eye color; but an unfortunate by-product of such inbreeding can be the emergence of characteristics such as deafness. A 1992 study of Dalmatians (by Strain and others, as reported in The Dalmatians Dilemma) found the following:

(i) 31% of all Dalmatians have blue eyes.
(ii) 38% of all Dalmatians are deaf.
(iii) 42% of blue-eyed Dalmatians are deaf.
What is the probability that a randomly chosen Dalmatian is blue-eyed and deaf?

Answer 1

0.1302 or 13.02%

Explanation:

So we know that 31% of the Dalmatians are blue eyed so that is 0.31. We also know that 42% of blue eyed Dalmatians are deaf so that is 0.42.

To find the probability of a blue eyed deaf Dalmatian we need 42% of 31%, so we need to do:

0.42 × 0.31 = 0.1302 or 13.02%