Question

Soundtronics is a company that manufactures inexpensive headphones at a high volume. Due to the high production rate, some of the headphones are defective when they come off of the production line. The probability that a set of headphones is defective is 0.39%. Find the probability that one of the first 30 sets of headphones are defective.
A.11%
B.12%
C.70%
D.99%

Answer 1

Answer:

The correct answer is 11%

Answer 2

Answer:

10.44%

Step-by-step explanation:

Given that

Soundtronics is a company that manufactures inexpensive headphones at a high volume. Due to the high production rate, some of the headphones are defective when they come off of the production line. The probability that a set of headphones is defective is 0.39%.

Let X be the no of defectives in the set of 30 sets.

THen since each set is independent of the other and if being defective is considered as a success,

then X is binomial with $p = 0.39% =0.0039\\q = 1-p=0.9961n =30$

The probability that one of the first 30 sets of headphones are defective.

=30C1pq^29

=0.1044

No option given matches with this

Answer is 10.44%