SOLUTION: If the probability that a student in the statistic class will score grade A in the final exams is 0.72, determine the probability that out of 5 students selected random from the cl

Question 469896: If the probability that a student in the statistic class will score grade A in the final exams is 0.72, determine the probability that out of 5 students selected random from the class at least 2 scored grade A?
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!

 

Hi,

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 = .72 & q =.28

nCx = 

5 students selected

P(at least 2 scored an A) = 1 - P(0 scoring an A) -P(1 scoring an A)

                          = 1 - (.28)^5 - 5(.72)^1(.28)^4 = .9762 

RELATED QUESTIONS

Suppose a student�s grade in a class is simply the mean of five 100-point
exams... (answered by Fombitz)
A student receives test scores of 62, 83, and 91. The student's final exam score is 88... (answered by JulietG)
If a student has an average exam score between 70 and 79, he will earn a grade of... (answered by t0hierry)
A Student has test scores of 72, 80, 65, 78, and 60. If the final exam counts as... (answered by Edwin McCravy)
Before the final exam, a student has test scores of 72, 80, 65, 78, and 60. If the final... (answered by ankor@dixie-net.com)
In a high school mathematics exam, 72% of the students score grade B and below while the... (answered by Boreal)
If a student has a current grade of 79% and gets a 0% on the final exam, which counts as... (answered by Theo)
Joe has scored 87, 92, and 82 on his first three exams in his math class. If the standard  (answered by solver91311)
If you have an 85% in a class and final is worth 25% of the grade.  What do you need to... (answered by Alan3354)