Probability Question 322

Question: A random variable has the following probability distribution

X: 0 1 2 3 4 5 6 7 P(x) 0 2p 2p 3p $ p^{2} $

$ 2p^{2} $

$ 7p^{2} $ 2p

Options:

A) $ \frac{1}{10} $

B) -1

C) $ \frac{3}{10} $

D) None

Show Answer

Answer:

Correct Answer: A

Solution:

$ \Sigma p(x)=1\Rightarrow 9p+10p^{2}=1 $
$ \Rightarrow 10p^{2}+9p-1=0\Rightarrow p=-1or\frac{1}{10} $
$ \therefore p=\frac{1}{10} $