(1 point) A certain typing agency employs two typists. The average number of errors per article is 2.42.4 when typed by the first typist and 4.54.5 when typed by the second. If your article is equally likely to be typed by either typist, find the probability that it will have no errors.

Respuesta :

Answer:

0.0509 is the probability that the article will have no mistakes.

Step-by-step explanation:

We are given the following in the question:

P(Typist A) = P(Typist B) = 0.5

P(typist A makes an error) = 2.4

The number of errors made by typist A is a Poisson distribution.

Formula:

[tex]P(X =k) = \displaystyle\frac{\lambda^k e^{-\lambda}}{k!}\\\\ \lambda \text{ is the mean of the distribution}[/tex]

[tex]\lambda_1 = 2.4[/tex]

We have to evaluate probability for no mistakes.

P(Typist A makes no mistake) =

[tex]P(x=0) = \dfrac{(2.4)^0e^{-2.4}}{0!} =0.0907[/tex]

P(typist B makes an error) = 4.5

The number of errors made by typist B is a Poisson distribution.

[tex]\lambda_2 = 4.5[/tex]

We have to evaluate probability for no mistakes.

P(Typist B makes no mistake) =

[tex]P(x=0) = \dfrac{(4.5)^0e^{-4,.5}}{0!} =0.0111[/tex]

P(article will have no error) =

P(Typist A)P(Typist A makes no mistake) + P(Typist B)P(Typist B makes no mistake)

[tex]=0.5\times 0.0907 + 0.5\times 0.0111\\=0.0509[/tex]

0.0509 is the probability that the article will have no mistakes.