SOLUTION: 3. From the previous experience it is known that 75% of all IT graduates get a job within three months of their graduation. In an IT college 25 students will graduate this semester

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Question 914294: 3. From the previous experience it is known that 75% of all IT graduates get a job within three months of their graduation. In an IT college 25 students will graduate this semester.
a) What is the probability that more than 18 will get a job within three months of their graduation?
b) What is the probability that between 12 and 15 graduates will get a job within three months of their graduation?
c) What are the mean and standard deviation of this distribution

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
p = .75, n = 25
a) 18/25 = .72, z(0.72) = (0.72-0.75)/sqrt[0.75*0.25/25)
P (x >18) = normalcdf(z, 100)
...........
b) zL = (.48-.75)/sqrt[0.75*0.25/25), zH = (.6 - .75)/sqrt[0.75*0.25/25)
P( 12 < x < 15) = normalcdf(zL,zH)
..........
mean = .75%2A25, sd = sqrt%28.75%2A.25%2A25%29