Question

An unfair coin is such that on any given toss, the probability of getting heads is 0.6 and the probability of getting tails is 0.4. The coin is tossed 8 times. Let the random variable X be the number of times heads is tossed.

1. Find P(X=5).

2. Find P(X≥3).

3. What is the expected value for this random variable?

E(X) =

4. What is the standard deviation for this random variable? (Give your answer to 3 decimal places)

SD(X) =

Answer 1

X : the number of times heads is tossed.

X ~ bin (n,p)

where, n = 8 ,p =0.6, q=0.4

the pmf of the distribution be:-

c). the expected value for this random variable is:-

d).the standard deviation for this random variable is:-

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