Question 1190135: Hi, please help me out!
A bag contains 8 blue, 7 red, 5 pink and 10 orange jelly beans. Six jellybeans are to be selected at random without replacement.
A. What type of distribution is this? (Uniform, Binomial, Geometric, or Hypergeometric)
B. What is the probability that at least one of the jelly beans picked is orange?
C. What is the expected number of pink jelly beans to be selected? (Which expectance formula should I use? They all vary for the type of distribution so I am confused)
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! 6 out of 30 is 30C6 possibilities
for pink NOT to be chosen at all, the probability is 25C6*5C0/30C6=0.2983, so the answer is the complement or 0.7017.
Also can be done by brute force with probability not is 25/30*24/29*23/28*22/27*21/26*20/25, which also equals 0.2983 with complement 0.7017, which is the answer.
-
E(x)=nK/N=6*5/30; the number of "good," if you will (5)*number of trials divided by total number.
=30/30, or 1
Brute force:
probability of 0 being chosen is 0.2983
probability of 1 is 5C1*25C5/30C6=0.4474
probability of 2 is 5C2*25C4/30C6=0.2130
of 3 is 0.0387
of 4 is 0.0025
of 5 is <0.0001
and x*p(x) summed will be 1.0 allowing rounding.
|
|
|
