Answer:
(a) 0.28347
(b) 0.36909
(c) 0.0039
(d) 0.9806
Step-by-step explanation:
Given information:
n=12
p = 20% = 0.2
q = 1-p = 1-0.2 = 0.8
Binomial formula:

(a) Exactly two will be drunken drivers.



Therefore, the probability that exactly two will be drunken drivers is 0.28347.
(b)Three or four will be drunken drivers.


Using binomial we get



Therefore, the probability that three or four will be drunken drivers is 0.3691.
(c)
At least 7 will be drunken drivers.

![P(x\leq 7)=1-[P(x=0)+P(x=1)+P(x=2)+P(x=3)+P(x=4)+P(x=5)+P(x=6)]](https://tex.z-dn.net/?f=P%28x%5Cleq%207%29%3D1-%5BP%28x%3D0%29%2BP%28x%3D1%29%2BP%28x%3D2%29%2BP%28x%3D3%29%2BP%28x%3D4%29%2BP%28x%3D5%29%2BP%28x%3D6%29%5D)
![P(x\leq 7)=1-[0.06872+0.20616+0.28347+0.23622+0.13288+0.05315+0.0155]](https://tex.z-dn.net/?f=P%28x%5Cleq%207%29%3D1-%5B0.06872%2B0.20616%2B0.28347%2B0.23622%2B0.13288%2B0.05315%2B0.0155%5D)
![P(x\leq 7)=1-[0.9961]](https://tex.z-dn.net/?f=P%28x%5Cleq%207%29%3D1-%5B0.9961%5D)

Therefore, the probability of at least 7 will be drunken drivers is 0.0039.
(d) At most 5 will be drunken drivers.



Therefore, the probability of at most 5 will be drunken drivers is 0.9806.
Answer:
The equation of circle C is ( x-5 )2 + ( y-7 )2 = 80 .
Step-by-step explanation:
You would plug in the y=9 into the first equation and then have the expression 9=9x-9
. After going through the first steps of solving an expression you would get 18=9x. X=2. Then you would plug in the x value into the first expression to get y=9.