SOLUTION: An exciting computer game is released. Some of the players who complete all the levels will buy an advanced version of the game. Suppose that 25% of the players buy an advanced ver

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Question 1160261: An exciting computer game is released. Some of the players who complete all the levels will buy an advanced version of the game. Suppose that 25% of the players buy an advanced version. In a group of 15 players,
i. what is the expected number of people who will buy the advanced version?[Ans. 3.75]
ii. What is the probability that at least two people will buy it?[Ans. 0.237]
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
mean is np, n=15 p=0.375 product is 3.75
what is probability 13 or 14 or 15 will not buy it with probability of 0.75 individually of not buying it.
for 15 it is 0.75^15=0.0134
for 14 it is 15* .75^14*0.25=0.0668
for 13 it is 15C2*0.75^13*0.25^2=0.1559
sum=0.23706 or 0.237