5.1The Bernoulli and Binomial Random Variables 143
0
0.25
0.20
0.15
0.10
0.05
0.0 123 45678910
Binomial (10, 0.5)
0
0.30
0.25
0.20
0.15
0.10
0.05
0.0 123 45678910
Binomial (10, 0.3)
0
0.30
0.25
0.20
0.15
0.10
0.05
0.0 123 45678910
Binomial (10, 0.6)
FIGURE 5.1 Binomial probability mass functions.
with parameters (10, .01). Hence the probability that a package will have to be replaced is
P{X> 1 }= 1 −P{X= 0 }−P{X= 1 }
= 1 −
(
10
0
)
(.01)^0 (.99)^10 −
(
10
1
)
(.01)^1 (.99)^9 ≈.005