SOLUTION: The probability that a student is late for statistics class is .2. There are 30 classes during the semster.
A. Find the probability that the student will be late exactly
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-> SOLUTION: The probability that a student is late for statistics class is .2. There are 30 classes during the semster.
A. Find the probability that the student will be late exactly
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Question 357981: The probability that a student is late for statistics class is .2. There are 30 classes during the semster.
A. Find the probability that the student will be late exactly 5 times.
B. Find the probability that he will be late fewer than 3 times.
C. Find the average number of times he will be late.
D. Find the standard deviation of the number of times he will be late. Found 2 solutions by ewatrrr, Fombitz:Answer by ewatrrr(24785) (Show Source):
Note: The probability of x successes in n trials is:
P = nCx* * where p and q are the probabilities of success and failure
respectively. In this case p(late) = .2 and q = .8
nCx =
A. Find the probability that the student will be late exactly 5 times.
P = 30C5* *
B. Find the probability that he will be late fewer than 3 times.
P( 0 lates) + P(1 lates) + P(late twice)
C. Find the average number of times he will be late.
Mean = n*p = 30*(.2) = 6 times
D. Find the standard deviation of the number of times he will be late.
Definition of standard deviation = =
You can put this solution on YOUR website! n=30
p=0.8
q=0.2
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C) Using EXCEL's BINOMDIST to generate all of the probability values from 0 to 30, then summing ,
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D) Again using EXCEL's BINOMDIST, the result from C), and then summing.
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