Question 1204801
.
The computer virus attacks a folder consisting of 28 files. The virus corrupts 
the files independently of each other. Each file is corrupted with a probability of 0.034. 
What is the probability that the virus will corrupt 4 files?
~~~~~~~~~~~~~~~~~~


<pre>
It is a binomial type experiment.

The number of trials is n= 28.
The number of success trials is k= 4.
The probability of success in each individual trial is p= 0.034.


Use the standard binomial formula for the probability

    P = {{{C[n]^k*p^k*(1-p)^(n-k)}}} = {{{C[28]^4*0.034^4*(1-0.034)^(28-4)}}} =

      = {{{20475*0.034^4*0.966^24}}} = 0.01193  (rounded).   <U>ANSWER</U>
</pre>

Solved.