Simple question, but I am a bit confused:
Given a working month of $28$ days, and let $Z$ be the number of days on which the sales exceed the target with a probability of $0.625$. Identify the distribution of $Z$ and find the probability that the sales exceed the target on $17$ days of the month.
I know that $Z\sim \text{Binomial}(n,p)$.
My question here is the number of trials, $n$, which is $28$ or $29$? Should I take $0$ as a probability for this?
If I only take $n= 28$, then my probability is $0.150045$.
If $n = 29$, then probability is $0.135978$.
Quite a difference there, any clarification would be appreciated.
((This post can be closed/deleted after I receive an answer as I don't think it will be of much help to others?))