SOLUTION: Let x be a binomial random variable with n = 7, p = 0.2. Find the following value. (Round your answer to three decimal places.) P(x > 1)

Algebra ->  Test -> SOLUTION: Let x be a binomial random variable with n = 7, p = 0.2. Find the following value. (Round your answer to three decimal places.) P(x > 1)      Log On


   

Question 1206638: Let x be a binomial random variable with n = 7, p = 0.2. Find the following value. (Round your answer to three decimal places.)
P(x > 1)
Found 3 solutions by MathLover1, Edwin McCravy, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
Answer by Edwin McCravy(20064) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be a binomial random variable with n = 7, p = 0.2.
Find the following value. (Round your answer to three decimal places.)
P(x > 1)
It is much easier to calculate P(x=0) and P(x=1) and subtract their sum
from 1:

P%28x=0%29%22%22=%22%22%22C%287%2C0%29%22%2A0.2%5E0%2A%281-0.2%29%5E%287-0%29%22%22=%22%22%281%29%281%29%280.8%29%5E7%22%22=%22%220.2097152
P%28x=1%29%22%22=%22%22%22C%287%2C1%29%22%2A0.2%5E1%2A%281-0.2%29%5E%287-1%29%22%22=%22%22%287%29%280.2%29%280.8%29%5E6%22%22=%22%220.3670016
P%28x%3C=1%29%22%22=%22%22P%28x=0%29%2BP%28x=1%29%22%22=%22%220.2097153%2B0.3670016%22%22=%22%220.5767168

P%28x%3E1%29%22%22=%22%221-P%28x%3C=1%29%22%22=%22%221-0.5767168%22%22=%22%220.4232832

Round to 0.423
 
Edwin

Answer by ikleyn(52883) About Me  (Show Source):
You can put this solution on YOUR website!
.

Only a person,  who does not know a subject,  may teach in a way as  @MathLover1 does it.

Her method to solve this problem is a classic example on how a student  SHOULD  NOT  do it.


In that sense,  it is very good that she posted her solution,

because it is good case and good opportunity for me to tell you :   NEVER  do it this way  ( ! )