A biotechnology company produced 196 doses of somatropin, including 9 which were defective. Quality control test 10 samples at random, and rejects the batch if any of the random samples are found defective. What is the probability that the batch gets rejected?

Respuesta :

Answer: 0.3756

Step-by-step explanation:

Given : A biotechnology company produced 196 doses of somatropin, including 9 which were defective.

Proportion of defective doses of somatropin : [tex]p=\dfrac{9}{196}=0.0459183673469\approx0.046[/tex]

Using binomial probability formula,

[tex]P(x)=^nC_xp^x(1-p)^{n-x}[/tex]

If Quality control test 10 samples at random, and rejects the batch if any of the random samples are found defective.

Then, the probability that the batch gets rejected will be :-

[tex]P(x\geq1)=1-P(x=0)\\\\=1-^{10}C_0(0.046)^0(1-0.046)^{10}\\\\=1-(1-0.046)^{10}\\\\=1-0.624429981287\\\\=0.375570018713\approx0.3756[/tex]

Hence, the probability that the batch gets rejected = 0.3756

Using the hypergeometric distribution, it is found that there is a 0.3821 = 38.21% probability that the batch gets rejected.

The samples are chosen without replacement, hence the hypergeometric distribution is used to solve this question.

What is the hypergeometric distribution formula?

The formula is:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

The parameters are:

  • x is the number of successes.
  • N is the size of the population.
  • n is the size of the sample.
  • k is the total number of desired outcomes.

In this problem:

  • There are 196 doses, hence N = 196.
  • 9 are defective, hence k = 9.
  • 10 are sampled, hence n = 10.

The probability that the batch gets reject, that is, the probability that there is at least one defective, is given by:

[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]

In which:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]P(X = 0) = h(0,196,10,9) = \frac{C_{9,0}C_{187,10}}{C_{196,10}} = 0.6179[/tex]

Then:

[tex]P(X \geq 1) = 1 - P(X = 0) = 1 - 0.6179 = 0.3821[/tex]

0.3821 = 38.21% probability that the batch gets rejected.

More can be learned about the hypergeometric distribution at https://brainly.com/question/24826394