# binomial probablity

#### danny.kay

##### New Member
According to National Highway traffic Safety Administration 66% of California motorists use seat belts. Find the probablity that in one group of 12 California motorists exactly 8 wear seat belts. Use the given Values of n,x and p. Use the binomial probablity formula as well.

Please, someone help me. I'm lost in this problem.

Thank you.

E

#### elnaz

##### Guest
hello
n=12
x=8
p=.66
X~bin(n,p) , p(X=x)=p(X=8)~0.2 of table of binomial

#### Foster

##### New Member
help

mean=500
standard deviation=100
What is -score for 585?
Use the -score to find the proportion of test scores that are less than 585?
What -score =70th percentile?
What raw score corresponds to the 70th percentile?

I am so confused. Is there anyone out there that can solve this for me or give me a clue?

#### nurserascal

##### New Member
hello
n=12
x=8
p=.66
X~bin(n,p) , p(X=x)=p(X=8)~0.2 of table of binomial
n is the population statistic in this problem.
x is the sample in this problem. and p = the precentile in the problem. am I understanding your answer correctly.
and you multiply all three to get the final answer..........correct??
i am also struggling to understand. thanks for your help
:tup:

E

#### elnaz

##### Guest
hello
you should study about binomial distribution
n:sample size
p: probability of success
x:number of success in sample size
in this question success is use seat belts