I would like to have some help with this problems:
A problem in a metal casting process of a part, called severe flashing results in scrapping the part that is being cast. A particular casting operation has in the past scrapped 10% of its parts due to severe flashing. Assume that scrapping a part or not scrapping a part in future operations is a binomial experiment with p=0.10.
1-Find the probability that no part is scrapped in the next 10 experiments.
b(x;n;p) is the binomial distribution.
where x =number os success
n=number of trial
p=probability of success
2- find the probability that at most two parts will be scrapped in the next operations.
My solution: B(2;10,0.10)
B(x;n,p) is the cumulative probabilities
3- Find the expected number of scrapped parts in the next 25 operations.
4- If the scrapping cost in n operation is the square of the number of parts scrapped, find the expected scrapping cost in the next 25 operations.
5- Find the probability that the third part scrapped is the 20th part cast.
To compute the expected value was supposed to have some some kinds of frequencies. That confused me a little since I don't see any.