SOLUTION: if a coin is biased so that P(H)=0.45 and P(T)=0.55 what will be the probability of two heads if a coin is tossed three times

Algebra.Com
Question 1039832: if a coin is biased so that P(H)=0.45 and P(T)=0.55 what will be the probability of two heads if a coin is tossed three times
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
This is a binomial distribution problem. The formula we will use is

(n C x)*(p^x)*(1-p)^(n-x)

where
p = 0.45 is the probability of heads
1-p = 0.55 is the probability of tails
n = 3 is the number of tosses
x = 2 is the number of heads we want
n C x refers to the combination formula

n C x = (n!)/(x!*(n-x)!)
3 C 2 = (3!)/(2!*(3-1)!)
3 C 2 = (3!)/(2!*1!)
3 C 2 = (3*2*1)/(2*1*1)
3 C 2 = 6/2
3 C 2 = 3

--------------------------------

So let's plug in the given values to get...


(n C x)*(p^x)*(1-p)^(n-x)
(3 C 2)*(0.45^2)*(1-0.45)^(3-2)
(3 C 2)*(0.45^2)*(0.55)^(1)
(3)*(0.45^2)*(0.55)^(1)
(3)*(0.45^2)*(0.55)
(3)*(0.2025)*(0.55)
0.334125

---------------------------------------------
---------------------------------------------

The final answer is 0.334125

RELATED QUESTIONS

Many everyday​ decisions, like who will drive to lunch or who will pay for the​... (answered by ikleyn)
A coin is biased so that a head is twice likely as a head. If the coin is tossed three... (answered by stanbon)
a coin is biased each flip you have 55% chance of getting a head . if you flip this... (answered by Boreal)
A coin is biased so that a head is twice as likely to occur as a tail. If the coin is... (answered by reviewermath)
An unfair coin has probability p of landing heads up on a single flip, where 0 < p < 1.... (answered by greenestamps)
5. You have two biased coins. Coin A comes up heads with probabaility ¼. Coin B comes up... (answered by richard1234)
question 1: A coin is biased to show 38% heads and 62% tails. The coin is tossed twice.... (answered by stanbon)
a fair coin was tossed 9 times and the coin landed on heads 7 times and tails twice. if... (answered by ikleyn)
A coin is biased so that the probability that it lands showing heads is 2/3.The coin is... (answered by Fombitz)