SOLUTION: Question A company claims that 80% of its trainees are promoted within the first year. Find the probabilities among 8 randomly selected trainees. 1.At least 6 will be promoted.

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Question 1057543: Question
A company claims that 80% of its trainees are promoted within the first year. Find the probabilities among 8 randomly selected trainees.
1.At least 6 will be promoted.
2.From 5 to 7 will be promoted
3.At most 6 will be promoted.
4. None will be promoted

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A company claims that 80% of its trainees are promoted within the first year. Find the probabilities among 8 randomly selected trainees.
1.At least 6 will be promoted.
P(6<= x <=8) = 1 - P(0<= x <=5) = 1-binomcdf(8,0.8,5) = 0.7969
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2.From 5 to 7 will be promoted
P(5<= x <=7) = binomcdf(8,0.8,7)-binomcdf(8,0.8,4) = 0.7760
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3.At most 6 will be promoted.
P(0<= x <=6) = binomcdf(8,0.8,6) = 0.4967
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4. None will be promoted
P(x = 0) = 0.2^8 = 0.00000256
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Cheers,
Stan H.
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