Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If the mean of a poisson distribution is $\frac{1}{3}$, then the ratio $P(X=1): P(X=2)$ is
MathematicsProbabilityAP EAMCETAP EAMCET 2021 (23 Aug Shift 2)
Options:
  • A $1: 2$
  • B $3: 1$
  • C $1: 6$
  • D $6: 1$
Solution:
1906 Upvotes Verified Answer
The correct answer is: $6: 1$
Given, Mean of Poisson distribution $=1 / 3$
For a Poisson distribution, the mean is equal to the parameter. Hence, the parameter is $1 / 3$.
$\therefore \quad P(X=1)=\frac{e^{-1 / 3}(1 / 3)^1}{1 !}$
$=e^{-1 / 3}(1 / 3)$
$P(X=2)=\frac{e^{-1 / 3}\left(\frac{1}{3}\right)^2}{2 !}$
$\therefore \quad P(X=1): P(X=2)=\frac{e^{-1 / 3}\left(\frac{1}{3}\right)}{\frac{e^{-1 / 3}\left(\frac{1}{3}\right)^2}{2 !}}$
$=\frac{2}{1 / 3}=\frac{6}{1}=6: 1$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.