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4 votes
2 answers
121 views

Confidence interval for the sum of 2 binomially distributed variables

$P_1$ and $P_2$ are uncorrelated, binomially distributed variables with success probabilities $p_1 \neq p_2$. Say I measure: $k_1 = 9$ successes out of $n_1 = 10$ trials for $P_1$ and $k_2 = 1000$ ...
dimitsev's user avatar
1 vote
0 answers
357 views

Probability of sum of sequences of integers

Let K be a positive integer.Suppose that the integers 1,2,3,...,3k+1are written down in random order.What is the probability that at no time during this process, the sum of the integers that have been ...
Win_odd Dhamnekar's user avatar
3 votes
1 answer
74 views

Summation of combinations up to $r-1$ terms

I am trying to come up with a simplified expression for $$\sum_{k=r}^{n}\binom{n}{k}$$ Choosing $x=y=1$ in Binomial theorem, I have $$2^n = \sum_{k=0}^{n}\binom{n}{k}$$ $$2^n = \sum_{k=0}^{r-1}\binom{...
Emon's user avatar
  • 31
2 votes
1 answer
417 views

difference between independent binomial variables

Let $X_1$ and $X_2$ be independent random variables where $X_1 \sim \mathrm{Bin}(m, 1/2)$ and $ X_2 \sim \mathrm{Bin}(n,1/2)$. How can we prove that $X_1 - X_2 + n \sim \mathrm{Bin}(m + n ,1/2)$? Can ...
ANUJ NAIN's user avatar
  • 663
6 votes
1 answer
148 views

multi stage binomial "process"

I wish to model the retransmission time of a file that divided into K blocks. I know the successful blocks of first transmission obey the binomial distribution $$ X_1 \sim \text B(K,p) $$ , p is the ...
robit's user avatar
  • 198