Statistics Examples
x>0 , n=3 , p=0.9
Step 1
Subtract 0.9 from 1.
0.1
Step 2
When the value of the number of successes x is given as an interval, then the probability of x is the sum of the probabilities of all possible x values between 0 and n. In this case, p(x>0)=P(x=1)+P(x=2)+P(x=3).
p(x>0)=P(x=1)+P(x=2)+P(x=3)
Step 3
Step 3.1
Use the formula for the probability of a binomial distribution to solve the problem.
p(x)=C13⋅px⋅qn-x
Step 3.2
Find the value of C13.
Step 3.2.1
Find the number of possible unordered combinations when r items are selected from n available items.
C13=Crn=n!(r)!(n-r)!
Step 3.2.2
Fill in the known values.
(3)!(1)!(3-1)!
Step 3.2.3
Simplify.
Step 3.2.3.1
Subtract 1 from 3.
(3)!(1)!(2)!
Step 3.2.3.2
Rewrite (3)! as 3⋅2!.
3⋅2!(1)!(2)!
Step 3.2.3.3
Cancel the common factor of 2!.
Step 3.2.3.3.1
Cancel the common factor.
3⋅2!(1)!(2)!
Step 3.2.3.3.2
Rewrite the expression.
3(1)!
3(1)!
Step 3.2.3.4
Expand (1)! to 1.
31
Step 3.2.3.5
Divide 3 by 1.
3
3
3
Step 3.3
Fill the known values into the equation.
3⋅(0.9)⋅(1-0.9)3-1
Step 3.4
Simplify the result.
Step 3.4.1
Evaluate the exponent.
3⋅0.9⋅(1-0.9)3-1
Step 3.4.2
Multiply 3 by 0.9.
2.7⋅(1-0.9)3-1
Step 3.4.3
Subtract 0.9 from 1.
2.7⋅0.13-1
Step 3.4.4
Subtract 1 from 3.
2.7⋅0.12
Step 3.4.5
Raise 0.1 to the power of 2.
2.7⋅0.01
Step 3.4.6
Multiply 2.7 by 0.01.
0.027
0.027
0.027
Step 4
Step 4.1
Use the formula for the probability of a binomial distribution to solve the problem.
p(x)=C23⋅px⋅qn-x
Step 4.2
Find the value of C23.
Step 4.2.1
Find the number of possible unordered combinations when r items are selected from n available items.
C23=Crn=n!(r)!(n-r)!
Step 4.2.2
Fill in the known values.
(3)!(2)!(3-2)!
Step 4.2.3
Simplify.
Step 4.2.3.1
Subtract 2 from 3.
(3)!(2)!(1)!
Step 4.2.3.2
Rewrite (3)! as 3⋅2!.
3⋅2!(2)!(1)!
Step 4.2.3.3
Cancel the common factor of 2!.
Step 4.2.3.3.1
Cancel the common factor.
3⋅2!(2)!(1)!
Step 4.2.3.3.2
Rewrite the expression.
3(1)!
3(1)!
Step 4.2.3.4
Expand (1)! to 1.
31
Step 4.2.3.5
Divide 3 by 1.
3
3
3
Step 4.3
Fill the known values into the equation.
3⋅(0.9)2⋅(1-0.9)3-2
Step 4.4
Simplify the result.
Step 4.4.1
Raise 0.9 to the power of 2.
3⋅0.81⋅(1-0.9)3-2
Step 4.4.2
Multiply 3 by 0.81.
2.43⋅(1-0.9)3-2
Step 4.4.3
Subtract 0.9 from 1.
2.43⋅0.13-2
Step 4.4.4
Subtract 2 from 3.
2.43⋅0.11
Step 4.4.5
Evaluate the exponent.
2.43⋅0.1
Step 4.4.6
Multiply 2.43 by 0.1.
0.243
0.243
0.243
Step 5
Step 5.1
Use the formula for the probability of a binomial distribution to solve the problem.
p(x)=C33⋅px⋅qn-x
Step 5.2
Find the value of C33.
Step 5.2.1
Find the number of possible unordered combinations when r items are selected from n available items.
C33=Crn=n!(r)!(n-r)!
Step 5.2.2
Fill in the known values.
(3)!(3)!(3-3)!
Step 5.2.3
Simplify.
Step 5.2.3.1
Cancel the common factor of (3)!.
Step 5.2.3.1.1
Cancel the common factor.
(3)!(3)!(3-3)!
Step 5.2.3.1.2
Rewrite the expression.
1(3-3)!
1(3-3)!
Step 5.2.3.2
Simplify the denominator.
Step 5.2.3.2.1
Subtract 3 from 3.
1(0)!
Step 5.2.3.2.2
Expand (0)! to 1.
11
11
Step 5.2.3.3
Divide 1 by 1.
1
1
1
Step 5.3
Fill the known values into the equation.
1⋅(0.9)3⋅(1-0.9)3-3
Step 5.4
Simplify the result.
Step 5.4.1
Multiply (0.9)3 by 1.
(0.9)3⋅(1-0.9)3-3
Step 5.4.2
Raise 0.9 to the power of 3.
0.729⋅(1-0.9)3-3
Step 5.4.3
Subtract 0.9 from 1.
0.729⋅0.13-3
Step 5.4.4
Subtract 3 from 3.
0.729⋅0.10
Step 5.4.5
Anything raised to 0 is 1.
0.729⋅1
Step 5.4.6
Multiply 0.729 by 1.
0.729
0.729
0.729
Step 6
Step 6.1
Add 0.027 and 0.243.
p(x>0)=0.27+0.729
Step 6.2
Add 0.27 and 0.729.
p(x>0)=0.999
p(x>0)=0.999