Answer:
P(2)=0.021942 approximately
P(2 or fewer)=0.02711 approximately
Step-by-step explanation:
[tex] P(x)=(n choose x) *p^x * q^{n-x} [/tex]
x is the number of successes desired
p is probability of getting a success per trial
n is the number of trials
q is 1-p
So n=15 and p=.4 here
And you want to know P(2) which means x is 2
Plug in this information
[tex] P(2)=(15 \text{ choose } 2) *.4^2 * .6^{15-2} [/tex]
Just plug into calculator... P(2)=0.021942 approximately
For p(2 or fewer) you just do P(0)+P(1)+P(2)
I already found P(2)
You need to find P(1)
Once you get P(1), add that result to 0.021942.
Try to do part b and I will tell you if you got it right or not.
So P(2 or less) is P(0)+P(1)+P(2)
So to complete this we need to find P(1) and almost forgot P(0)...
We already have P(2).
P(0)=(15 choose 0) *.4^0*.6^(15-0)=0.00047
P(1)=(15 choose 1) *.4^1 *.6^(15-1)=.004702
Now P(2)=0.021942
--------------------------add these
0.027114 approximately
