Question 1194836
<font color=black size=3>
p = probability of success
p = probability of a person staying with the same company for more than five years
p = 0.08


n = sample size
n = 11


Binomial Probability Formula
P(x) = ( nCx ) * p^x * (1-p)^(n-x) 
P(4) = ( 11C4 ) * 0.08^4 * (1-0.08)^(11-4) 
P(4) = ( 330 ) * 0.08^4 * (1-0.08)^(11-4) 
P(4) = 0.0075403009396 approximately
P(4) = <font color=red>0.0075</font>


The 11C4 refers to the nCr notation
The scratch work is shown below
n = 11, r = 4
n C r = (n!)/(r!(n-r)!)
11 C 4 = (11!)/(4!*(11-4)!)
11 C 4 = (11!)/(4!*7!)
11 C 4 = (11*10*9*8*7!)/(4!*7!)
11 C 4 = (11*10*9*8)/(4!)
11 C 4 = (11*10*9*8)/(4*3*2*1)
11 C 4 = (7920)/(24)
11 C 4 = 330


Answer: <font color=red>0.0075</font> (approximate)
</font>