Finite Math Examples
x=2x=2 , n=3n=3 , p=0.2p=0.2
Step 1
Use the formula for the probability of a binomial distribution to solve the problem.
p(x)=C23⋅px⋅qn-x
Step 2
Step 2.1
Find the number of possible unordered combinations when r items are selected from n available items.
C23=Crn=n!(r)!(n-r)!
Step 2.2
Fill in the known values.
(3)!(2)!(3-2)!
Step 2.3
Simplify.
Step 2.3.1
Subtract 2 from 3.
(3)!(2)!(1)!
Step 2.3.2
Rewrite (3)! as 3⋅2!.
3⋅2!(2)!(1)!
Step 2.3.3
Cancel the common factor of 2!.
Step 2.3.3.1
Cancel the common factor.
3⋅2!(2)!(1)!
Step 2.3.3.2
Rewrite the expression.
3(1)!
3(1)!
Step 2.3.4
Expand (1)! to 1.
31
Step 2.3.5
Divide 3 by 1.
3
3
3
Step 3
Fill the known values into the equation.
3⋅(0.2)2⋅(1-0.2)3-2
Step 4
Step 4.1
Raise 0.2 to the power of 2.
3⋅0.04⋅(1-0.2)3-2
Step 4.2
Multiply 3 by 0.04.
0.12⋅(1-0.2)3-2
Step 4.3
Subtract 0.2 from 1.
0.12⋅0.83-2
Step 4.4
Subtract 2 from 3.
0.12⋅0.81
Step 4.5
Evaluate the exponent.
0.12⋅0.8
Step 4.6
Multiply 0.12 by 0.8.
0.096
0.096