SOLUTION: Of 41 bank accounts at small bank, 21 accounts have values of less than $1000 and the rest have values of at least $1000. Suppose 5 accounts are randomly sampled. What is the p

Algebra ->  Probability-and-statistics -> SOLUTION: Of 41 bank accounts at small bank, 21 accounts have values of less than $1000 and the rest have values of at least $1000. Suppose 5 accounts are randomly sampled. What is the p      Log On


   



Question 945044: Of 41 bank accounts at small bank, 21 accounts have values of less than $1000 and the rest have values of at least $1000. Suppose 5 accounts are randomly sampled.
What is the probability that exactly 4 of the 5 accounts have values of at least $1000?

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Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The probability of an account having less than $1000 is
P=21%2F41
So the probability of an account having at least $1000 is
P=1-21%2F41=41%2F41-21%2F41=20%2F41
.
.
Choosing 5 at random and having exactly 4 at least $1000 (Y) and 1 less than $1000 (X), gives you 5 possible outcomes.
XYYYY
YXYYY
YYXYY
YYYXY
YYYYX
So then the probability would be,
P=5%2A%2820%2F41%29%5E4%2A%2821%2F41%29
P=5%2A.0566%2A0.5122
P=0.145