Question

There are currently 18 pit bulls at the pound. Of the 18 pit bulls, four have attacked another dog in the last year. Joe, a member of the staff, randomly selects six of the pit bulls for his group. What is the probability that at least one of the pit bulls in Joe's group attacked another dog last year?

Answer 1

Answer: 0.7748

Step-by-step explanation:

Given : Number of bit bulls at the pound = 18

Number of pit bulls have attacked another dog in the last year =4

The proportion of pit bulls have attacked another dog in the last year:$p=\dfrac{4}{18}\approx0.22$

Number of the pit bulls selected = 6

The probability of that none of the pit bulls in Joe's group attacked another dog last year :  $P(0)=(1-0.22)^6=0.225199600704\approx0.2252$

By using binomial , the probability that at least one of the pit bulls in Joe's group attacked another dog last year is given by :-

$P(x\geq 1)=1-P(x$

Hence, the required probability = 0.7748