Question

The probability that a randomly chosen citizen-entity of Cygnus is of pension age is approximately 0.7. What is the probability that, in a randomly selected sample of 3 citizen-entities, all of them are of pension age? Round your answer to four decimal places.

Answer 1

\[P(all\ 3\ of\ pension\ age)=\left(\begin{matrix}3 \\ 3\end{matrix}\right)0.7^{3}0.3^{0}=(0.7)^{3}=you\ can\ calculate\]

Answer 2

oh so this is the same set up as before.. how do you distinguish what is n and r

Answer 3

n is the sample size. r is the number of successes. In this question the sample size is 3 and the number of successes is also 3.