SOLUTION: Let x be a random variable that denotes the number of tails obtained when three coins are tossed? a. Find E(X) = ........ I solved this one, 1.5 b. Find the P(x < or = to 2)

Algebra.Com
Question 1174544: Let x be a random variable that denotes the number of tails obtained when three coins are tossed?
a. Find E(X) = ........ I solved this one, 1.5
b. Find the P(x < or = to 2) for the random variable
c. Find the P(x<5) for the random variable
Answer by ewatrrr(24785)   (Show Source): You can put this solution on YOUR website!

Hi
  Binomial Theorem
       N = 3 coins tossed               p(H)=1/2   and q(T)=1/2 

 P(x ≤ 2) = P(x=0) + P(x=1) + P(x=2)
P(x=0) + P(x=1) + P(x=2) = 3C0(1/2^)3 + 3C1(1/2)^3 + 3C2(1/2)^3 
     (1/8) + (3/8) + (3/8)  = .875

  P(x < 5) = 1   
 NOte: P(x=0) + P(x=1) + P(x=2) + P(x=3) = .875 + .125 = 1

Wish You the Best in your Studies.


RELATED QUESTIONS

Construct a probability histogram for the binomial random variable, X. Three coins are (answered by Fombitz)
Suppose a fair coin is tossed three times. Let X be the random variable that represents... (answered by yurtman,ikleyn)
3. Four coins are tossed. Let Y be the random variable representing the number of heads... (answered by ikleyn)
Let x be the absolute difference between the number of heads and the number of trials... (answered by stanbon)
A fair coin is tossed three times. Let X be the number of heads in the tosses minus the... (answered by Edwin McCravy)
Let X be the number of tails that turned up when two fair coins are tossed. What are the... (answered by ikleyn)
It is known that a certain hockey goalie will successfully make a save 86.23% of the... (answered by Theo)
Use a diagram to list the sample space showing the possible arrangements of heads and... (answered by stanbon)
A fair coin is tossed four times, let x be a random variable representing the number of... (answered by mathmate)