A brand name has a 40​% recognition rate. If the owner of the brand wants to verify that rate by beginning with a small sample of 5 randomly selected​ consumers, find the probability that exactly 2 of the 5 consumers recognize the brand name. Also find the probability that the number who recognize the brand name is not 2.

Respuesta :

Answer:

1) 0.3456

2) 0.6544.

Step-by-step explanation:

Let X represents the event of recognizing the brand,

Given,

The probability of recognizing the brand, p = 40​% = 0.40,

Thus, the probability of not recognizing the brand, q = 1 - 0.40 = 0.60,

Since, the binomial distribution formula,

[tex]P(x) = ^nC_r (p)^r(q)^{n-r}[/tex]

Where,

[tex]^nC_r=\frac{n!}{r!(n-r)!}[/tex]

1) Thus, the probability that exactly 2 of the 5 consumers recognize the brand name is,

[tex]P(X=2)=^5C_2 (0.40)^2 (0.60)^{5-2}[/tex]

[tex]=10 (0.40)^2 (0.60)^3[/tex]

[tex]=0.3456[/tex]

2) Also, the probability that the number who recognize the brand name is not 2 = 1 - P(X=2) = 1 - 0.3456 = 0.6544.

Q&A Education