Answer:
Probability that no more than 2 out of 12 parts tested are defective is 0.8891.
Step-by-step explanation:
We are given that the probability that a machine part is defective is 0.1.
Twelve parts are selected at random.
The above situation can be represented through binomial distribution;
where, n = number trials (samples) taken = 12 parts
r = number of success = no more than 2
p = probability of success which in our question is probability that
a machine part is defective, i.e; p = 0.1
<u><em>Let X = Number of machine parts that are defective</em></u>
So, X ~ Binom(n = 12, p = 0.1)
Now, Probability that no more than 2 out of 12 parts tested are defective is given by = P(X 2)
P(X 2) = P(X = 0) + P(X = 1) + P(X = 2)
=
=
= 0.8891
Therefore, probability that no more than 2 out of 12 parts tested are defective is 0.8891.