Question 130945
Find these probabilties for a sample of 20 teenagers is 70% of them had compact disk players by the age of 16. 
a. P(At least 14 had CD players) = 1 - binomcdf(20,0.7,13)=0.608 
b. P(Exactly 9 had CD players) = 20C9(0.7)^9*0.3^11 or binompdf(20,0.7,9)=0.012
c. P(More than 17 had CD players) = 1 - binomcdf(20,0.7,17) = 0.03548...
-------------------
Cheers,
Stan H.