Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Can you help me to understand the answer to this question?
Question: Among companies doing highway/bridge construction. 81% test employees for substance abuse. A study involves the random selection of 8 companies.
a) Find the probability that at least half (4 or more) of the companies test for substance abuse.
answer:
X P(x)
0 .000002
1 .000058
2 .000864
3 .007369
4 .039269
5 .133929
6 .285480
7 .347787
8 .185302
= .99171
My teacher gave us the answer key and I don't understand how he got the values in the table. Can anyone explain that to me?
1 Answer
- 9 years agoFavorite Answer
The values in the table are from the Binomial Distribution.
X ~ Bin(8,0.81) because there are 8 trials (n=8) with the probability of 81% of success in each (p=.81).
The probabilities in the table are from P(x) = (nCx)*p^x*(1-p)^(n-x)
Where nCx is n!/x!(n-x)!
