SOLUTION: At a Bangalore High School, 20% of fourth semester mathematics students retake their C1 module. There are 15 students in one of the professor’s class; find the probability that p

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Question 1120609: At a Bangalore High School, 20% of fourth semester mathematics
students retake their C1 module. There are 15 students in one of the
professor’s class; find the probability that precisely four of them retake this
module.



















Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Number of ways that 4 out of the 15 retake the module: 15 choose 4

15C4 = 1365

Probability that a particular 4 students will retake the module (probability .20) and the other 11 will not (probability .80):
(.20)^4 * (.80)^11 = (some small number)

The probability is then 1365 times that small number: 0.1876 to 4 decimal places.