<h3>Answer:</h3>
- A — 1
- B — ∑[k=0..2] 15Ck(.24^k)(.76^(15-k))
- D — 12 and 3.1
- A — 0.1091
- B — 0.83 ...
<h3>Explanation:</h3>
1. The probability is 0.52 that the officer will pull over a driver and then the expected number more. So, if x is the expected number of drivers pulled over until one is not texting, we have ...
... x = 0.52(1+x)
... 0.48x = 0.52
... x = 0.52/0.48 = 13/12 = 1 1/12 ≈ 1 . . . . matches selection A
(<em>Comment on this result</em>: I find it interesting that these are the odds in favor of finding a driver who texts. That is, if the probability of texting is 0.98, the odds are 49:1 that a driver will be texting, and the expected number of pull-overs is 49.)
2. The probability of at most 2 being cured is the probability of 0, 1, or 2 being cured. You need to add up those probabilities. The sum in answer selection B does that.
3. The mean of a binomial distribution is ...
... μx = np = 60·0.2 = 12
... σx = √(np(1-p)) = √(12·0.8) ≈ 3.0984
These match selection D.
4. 20C14(0.8^14)(0.2^6) = 38760·.043980·0.000064 ≈ 0.109100 . . . matches A
5. mean(x) = 0.94; mean(x^2) = 1.58, so ...
... σx = √(1.58 -0.94²) ≈ 0.83 . . . . matches selection B
Answer:
United Nations Conference on Environment and Development(UNCED)
Explanation:
The conference was held in 1992 at Rio de Janeiro, Brazil (June 3–14, 1992), to reconcile worldwide economic development with protection of the environment, The Statement of Principles on Forests, aimed at preserving the world’s rapidly vanishing tropical rainforests, is a nonbinding statement recommending that nations monitor and assess the impact of development on their forest resources and take steps to limit the damage done to them.
Because out of that very low chance of winning there a 30 you can win