Answer:
The correct approach will be "0.612580".
Step-by-step explanation:
Given:
Randomly selected customers,
n = 10
Probability of recognition,
p = 90%
or,
= 0.9
q = 1 - p
= 1 - 0.9
= 0.1
Now,
The probability that 9 out of 10 clients are likely to be familiar with the brand will be:
⇒ [tex]P(X=r)=nCr\times (p)^r\times (q)^{(n-r)}[/tex]
⇒ [tex]P(X=9)=10C_9\times (0.9)^9\times (0.1)^{(10-9)}[/tex]
[tex]=10C_9\times (0.9)^9\times (0.1)^1[/tex]
[tex]=10\times (0.9)^9\times 0.1[/tex]
[tex]=0.387420[/tex]
hence,
The probability that not nine seem to be the numbers recognizing her brand name will be:
⇒ [tex]P(X=not \ 9)=1-P(X=9)[/tex]
[tex]=1-0.387420[/tex]
[tex]=0.612580[/tex]