A) \[\frac{n-k}{k-1}.\frac{p}{q}\]
B) \[\frac{n-k+1}{k}.\frac{p}{q}\]
C) \[\frac{n+1}{k}.\frac{q}{p}\]
D) \[\frac{n-1}{k+1}.\frac{q}{p}\]
Correct Answer: B
Solution :
Here mean = np and variance = npq \[\therefore \]\[\frac{P(X=k)}{P(X=k-1)}=\frac{^{n}{{C}_{k}}{{(p)}^{k}}{{(q)}^{n-k}}}{^{n}{{C}_{k-1}}{{(p)}^{k-1}}{{(q)}^{n-k+1}}}=\frac{^{n}{{C}_{k}}}{^{n}{{C}_{k-1}}}.\frac{p}{q}\] \[\therefore \]\[\frac{P(X=k)}{P(X=k-1)}=\frac{n-k+1}{k}\,.\,\frac{p}{q}\].
You need to login to perform this action.
You will be redirected in
3 sec
