Binomial Definition and 668 Threads

In probability theory and statistics, the binomial distribution with parameters n and p is the discrete probability distribution of the number of successes in a sequence of n independent experiments, each asking a yes–no question, and each with its own Boolean-valued outcome: success (with probability p) or failure (with probability q = 1 − p). A single success/failure experiment is also called a Bernoulli trial or Bernoulli experiment, and a sequence of outcomes is called a Bernoulli process; for a single trial, i.e., n = 1, the binomial distribution is a Bernoulli distribution. The binomial distribution is the basis for the popular binomial test of statistical significance.
The binomial distribution is frequently used to model the number of successes in a sample of size n drawn with replacement from a population of size N. If the sampling is carried out without replacement, the draws are not independent and so the resulting distribution is a hypergeometric distribution, not a binomial one. However, for N much larger than n, the binomial distribution remains a good approximation, and is widely used.

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  1. T

    What Is the Minor Value of n in the Newton Binomial Problem?

    Homework Statement Find the minor value of the natural number n such that \left (\frac{\sqrt{3}}{2} + \frac{1}{2}i \right )^{n} be a real positive number. EDIT: n must not be 0. Homework Equations Considering the binomial theorem as: {\left(x+y\right)}^n=\sum_{k=0}^n{n \choose...
  2. A

    Relationship b/w Binomial, CLT & Poisson Distrib.

    From the central limit theorem the binomial distribution can be approximated by a normal distribution N(0,1). But the binomial distribution can also be approximated by a poisson distribition. Does this mean there is a relationship between the normal distribution and the poisson distribution...
  3. M

    Help with negative binomial distributions

    One of the questions in my probability homework reads: X denotes a negative binomial random variable, with p = 0.6 Find P(X ≥ 3) for a) r = 2 and b) r = 4. According to my teacher, the answers are 0.1792 and 0.45568, respectively, but I can't for the life of me figure out how he got them...
  4. I

    Calculating Binomial Probability: Understanding Output

    Hi, I'm using a website (http://stattrek.com/Tables/Binomial.aspx) to calculate binomial probability, and I cannot understand it's output. Consider: 1.13860032513458E-11 Does this mean 1.13860032513458^[e*(-11)] Thanks
  5. M

    How Does the Binomial Coefficient Relate to Subsets of Binary Sequences?

    Homework Statement Show that: (\stackrel{n}{k})=\#\left\{(\omega_{1},..., \omega_{n})\in\left\{0,1\right\}^{n}:\Sigma^{n}_{l=1}\omega_{l}=k\right\} (edit: the sigma is meant to go from l=1 to n) Homework Equations It says to use this...
  6. T

    Where is the Mistake in My Extended Binomial Theorem Calculation?

    Homework Statement Calculate \sqrt{1/20} using the extended binomial theormem. (a precision of k=4 is enough) The Attempt at a Solution \sqrt{1/20}= (1 + (-19/20) )^{1/2}= \sum( choose (1/2,k)*(-19/20)^k) = 1- 1/2*19/20-1/8*361/400+1/16*6589/8000 = 0.72... is wrong. Homework...
  7. Y

    Binomial Theoreom and Trigonometry

    Homework Statement Express cos^4Θ.sinΘ in the form asinΘ+bsin3Θ+csin5Θ Homework Equations cosrΘ = 1/2(z^r + z^-r) sinrΘ = 1/2i(z^r - z^-r) The Attempt at a Solution So far I think I have this. 32i(sinΘ)(cos^4Θ) = (z-z^-1)(z+z^-1)^4 I am unsure how to multiply and manipulate...
  8. Y

    Finding a term in a binomial expnasion

    Homework Statement Find the term in the expansion of (x-(2/x^2))^14 which is of the form constant/x. The Attempt at a Solution I have worked out the general expression. (14|r) x^14-r * (-2/x^2)^r However I can only work out this problem by trial and error. I know that in this case...
  9. silvermane

    Combinatorial Proofs of a binomial identity

    Homework Statement Show that for all integers n,m where 0 ≤ m ≤ n The sum from k=m to n of {(nCk)*(kCm)} = (nCm)*2^(n-m) The Attempt at a Solution So for the proof, I have to use a real example, such as choosing committees, binary sequences, giving fruit to kids, etc. I have been...
  10. silvermane

    Combinatorial Proofs of Binomial Identities

    Homework Statement (Give a combinatorial proof of each of the following identities. In other words, describe a collection of combinatorial objects and then explain two different methods for counting those objects. Leave each identity in the form given. Do not rearrange terms or use any other...
  11. E

    Binomial Probability Clarification

    Homework Statement For fixed n, are there values of p (0≤p≤1) for which V(X) = 0? Explain why this is so. The Attempt at a Solution For X~Bin(n,p), V(X)=np(1-p). So the only solutions for this equation are when p=0 or p=1. There are too many variables for me to keep track of and...
  12. E

    Binomial Probability Distribution

    Homework Statement The College Board reports that 2% of the 2 million high school students who take the SAT each year receive special accommodations because of documented disabilities. Consider a random sample of 25 students who have recently taken the test. a.) What is the probability...
  13. L

    What Is the Minimum Number of Articles Needed for a 75% Acceptance Probability?

    Homework Statement The rejection rate of a certain journal is 45%. If the journal accepts articles at random, what is the minimum number of articles someone has to submit to have a probability of more than 0.75 of getting at least one article accepted? Homework Equations I'm almost sure...
  14. P

    Binomial probability distribution integration limits

    Homework Statement I am trying to find the limits of integration (upper and lower) of a known value of the binomial probability distribution. In other words, I know what the integral (area under the prob. dist.) needs to be (0.84 and 0.16), but how can I code a function (say into MATLAB) that...
  15. D

    How to Verify the 5th Term of the Binomial Expansion of (3-2/x)^9?

    hi there I am abit stuck here. i got a q saying : in binomial expansion of (3-2/x)^9 find the 5th term using the general term of the binomial expansion and check your answer (3-2/x)^9 used formula =N!/(n-r)!r! * A^(n-r) * b ^ r r= 4 a= 3 b= - 2/x n=9 got a answer of -489888/x^4 How do i...
  16. J

    Proving Binomial Coefficients for Even n | Combinatorial Argument

    Suppose n is even, prove: \sumk=0->n/2, C(n,2k)=2^(n-1)=\sumk=1->n/2, C(n,2k-1) Give a combinatorial argument to prove that: (I've figured out this one...) \sumk=1->n, C(n,k)^2=C(2n,n) For the first problem, I tried to break C(n, 2k) into C(n+1,2k)-C(n, 2k-1), but they didnt seem to work very...
  17. R

    Expectation of a Negative Binomial RV

    Homework Statement Consider a Negative Binomial random variable Y ~ NB(r, p). Show (from first principles!) that E[Y] is r/p. Why does this imply Y is proper? Homework Equations I have no idea how to use latex, so this may be messy: pmf of Y: [ (k+r-1)! / k!(r-1)! ] * (1-p)^r * p^k...
  18. T

    Binomial Theorem & Nilpotent Elements in a Ring: Is (a+b)m+n Nilpotent?

    I have this question and its a combination of the binomial theorem and nilpotent elements within a ring. Suppose the following, am=bn=0. Is it necessarily true that (a+b)m+n is nilpotent. For this question I did the following: \sumi=0m+n\binom{m+n}{i}am+n-ibi If i=m, then a=0...
  19. K

    Poisson and binomial distributions, corrupted characters in a file

    A text file contains 1000 characters. When the file is sent by email from one machine to another, each character (independent of other characters) has probability 0.001 of being corrupted. Use a poisson random variable to estimate the probability that the file is transferred with no errors...
  20. A

    Binomial probability, similar to lottery problems.

    Homework Statement An opaque bag contains 10 green counters, and 20 red ones. One counter is drawn at random and not replaced: green scores one, red scores zero. Five counters are drawn. Find the probability of scoring 0, 1, 2, 3, 4, 5 points. Homework Equations The Attempt at...
  21. icystrike

    Binomial Expansion: Coeff of x^29 in (1+x^5+x^7+x^9)

    Homework Statement Find the coefficient of x^{29} in the expansion of (1+x^{5}+x^{7}+x^{9}).Homework Equations The Attempt at a Solution
  22. F

    A comparison on binomial expansion

    Could anyone help me on this question? Is it true that \sum_{k=n+1}^{2n}\left(\begin{array}{c} 2n\\k\end{array}\right)x^{k}\left(1-x\right)^{2n-k}\leq2x for any x\in(0,1) and any positive integer n? Any help on that will be greatly appreciated!
  23. 2

    Understanding Binomial Coefficients: n Choose r

    Hey guys, I've been reading up on binomial coefficients and I have found a brief section on n choose r. I understand vaguely what it actually is, however in my textbook there is a step by step proof of how we show that: ( \stackrel{n}{r} ) = \frac{n!}{r!(n-r)!} I can follow where...
  24. E

    Negative binomial, Poisson, or gambler's ruin?

    Homework Statement . Peter and Paul bet one dollar each on each game. Each is willing to allow the other unlimited credit. Use a calculator to make a table showing, to four decimal places, for each of p = 1/10, 1/3, .49, .499, .501, .51, 2/3, 9/10 the probabilities that Peter is...
  25. A

    Probability Theory ; Binomial Distribution?

    Homework Statement Now you and your fiend play a different game. You flip your coin until it comes up heads the first time. Let X denote the number of flips needed. Your friend rolls its die until it comes up "3" or "5". The first try let Y denote the number of rolls needed. Assume X and Y are...
  26. Q

    Hypothesis Testing: Binomial Experiment

    Homework Statement A drug company markets a medication that cures about 60% of cases with depression. A CB program is thought to be more effective. It was delivered to 15 depressed people. Determine the minimum number of cured people required to support the claim that the CB program is more...
  27. O

    Covariance of Binomial Random Variables

    Homework Statement Let X be the number of 1's and Y be the number of 2's that occur in n rolls of a fair die. Find Cov(X, Y) Homework Equations Cov(X,Y) = E(XY) - E(X)E(Y) The Attempt at a Solution Both X and Y are binomial with parameters n and 1/6. Thus it is easy to find E(X)...
  28. I

    Proving the Evenness of (\stackrel{2n}{n}) Using the Binomial Theorem

    Homework Statement prove that (\stackrel{2n}{n}) is even when n \geq1 Homework Equations as a hint they gave me this identity: \stackrel{n}{k}= (n/k)(\stackrel{n-1}{k-1}) The Attempt at a Solution by using that identity i got: (\stackrel{2n}{n}) = (2n/n)...
  29. L

    Binomial Expansion: Coefficient of p4q7 in (2p-q)(p+q)10

    Homework Statement Determine the coefficient of p4q7 in the expansion of (2p-q)(p+q)10Homework Equations The Attempt at a Solution sry, i can't attempt to solve this coz i don't even know how to expand this using formula
  30. H

    Binomial Theorem and Modular Arithmetic Proof Check

    Homework Statement \mbox{Prove or give a counterexample: If p is a prime integer, then for all integers x and y, } (x+p)^p \equiv_p x^p+y^p. Homework Equations \equiv_p \mbox{just means (mod p). Can you please check and see if this proof is well-formed?} The Attempt at a Solution...
  31. K

    Probability Mass Functions of Binomial Variables

    Homework Statement Let X and Y be independent binomial random variables with parameters n and p. Find the PMF of X+Y. Find the conditional PMF of X given that X+Y=m. Homework Equations The PMF of X is P(X=k)=(n C k)pk(1-p)n-k The PMF for Y would be the same. The Attempt at a...
  32. A

    Binomial Distribution Probability

    Let X be a Binomial B(\frac{1}{2},n), where n=2m. Let a(m,k) = \frac{4^m}{(\stackrel{2m}{m})}P(X = m + k). Show that lim_{m->\infty}(a(m,k))^2 = e^{-k^2}. So far, I've found that P(X = m+k) = (\stackrel{2m}{m+k}) \frac{1}{4^m} Then, a(m,k)=\frac{m!m!}{(m+k)!(m-k)!}. But I have no...
  33. B

    Understanding the Simplification of Binomial Coefficients

    Here is the problem i am having trouble: Expressing the binomial coefficients in terms of factorials and simplifying algebraically show that (n over r) = (n-2+1)/r (n over r-1) i got that equals ((n-r+1)/r) ((n!)/((r-1)!(n-(r-1))!)) but i am trying to get that to equal n!/r!(n-r)! which...
  34. L

    Question regarding binomial random variable and distribution

    Hi, just started learning probability & need some help in understanding... "The binomial random variable X associated with a binomial experiment consisting of n trials is defined as X = the number of S's among the n trials. Suppose, for example, that n = 3. Then there are 8 possible...
  35. P

    Uncertainty on the number of trials in binomial distributions?

    Dear Reader, I am writing for information, or a point towards any information about the calculation on the uncertainty on the number of trials in a binomial distribution. I had been using the SQRT(N) (taken from poisson dist. I miss them) but forgot they are binomial. For example if I toss a...
  36. M

    Binomial distribution formulae?

    [b]1. Let the p.m.f. pf M be defined by f(m)=x/8, x=1,3,4. What is the mean of M? [b]2. n!/n-r*p^n*(1-p)^n-r [b]3. 3!*1/3^3*2/3^2=.59 This is not the correct answer!
  37. C

    Solving 31.2^(1/5) ≈ 197/99 with Binomial Expansion

    Hi, its me again. \left(1 - x\right)^{\frac{1}{5}} show that 31.2^{\frac{1}{5}} \approx \frac{197}{99} how can i know what value should x be ?
  38. P

    Uncertainty of binomial distribution?

    Hi, I'd like to know how to find the uncertainty of a function that has two binomial distribution s, something like Signal = N(yes) - N(no) Set p = 0.6 for yes. My problem is that I do not know how to find the uncertainty for N(yes) and N(no), and do not know how to find the uncertainty...
  39. B

    Binomial approximation using Mellin transform

    I know how to derive the binomial approximation for (1+\alpha x)^{\gamma} using a Mellin transform, but for (1-\alpha x)^{\gamma} the method appears to fail because I can't take x to infinity. Here is the basics of the method. Take the Mellin transform of (1+\alpha x)^{\gamma}: M(p) =...
  40. G

    Why Does the Binomial Theorem Solution Differ from the Book's Answer?

    Homework Statement Homework Equations Formula => C(n,r) or nCr =n!/r!(n-r)! & the basic Binomial Theorem formula. *Answer mentioned in book = nx The Attempt at a Solution The LHS should be (x+y)n & the given question is its expansion only if that 'r' is not multiplied in the question. I...
  41. P

    Arithmetic Progression + System of equations + binomial

    Homework Statement A third degree polynomial has 3 roots that, when arranged in ascending order, form an arithmetic progression in which the sum of the 3 roots equal 9/5. The difference between the square of the greatest root and the smallest root is 24/5 Given that the coefficient of the...
  42. P

    Why is Adding One Necessary in Binomial Series for 1/\sqrt{1-x^{2}}?

    When using a binomial series to expand 1/\sqrt{1-x^{2}} I come up with the correct answer except that I do not add the number one to my answer. Why do I have to add one to the series, should this not arise when calculating the sum?
  43. C

    Binomial Distribution: Solving for P(X=2, N=4), P(X=1), and P(N=4|X=1)

    Homework Statement Suppose that the conditional distribution of X given that N = n is binomial (n, 1/2) and the distribution of N is uniform over {2,4,6} a) Determine P(X=2, N = 4) b) Determine P(X=1) c) Determine P(N = 4| X =1) Homework Equations The Attempt at a Solution...
  44. C

    Binomial + Condition Distribution

    Homework Statement Let X be a binomial random variable representing the number of successes in n independent Bernoulli trials. Let Y be the number of successes in the first m trials, where m < n . Find the conditional probability distribution of Y given X=x. Homework Equations The...
  45. M

    The break down of a negative binomial equation

    Firstly, I want to note I'm a post college student who is attempting to teach himself calculus. I'm reading Calculus Made Easy by Silvanus P. Thompson and Martin Gardner, St. Martin's Press, 1998 ed. My question comes from page 56 Case of a Negative Exponent y + dy= (x + dx)^-2...
  46. E

    Binomial Theorem: Exploring the Summation Equation

    Hello, All we know the Binomial Theorm which may be stated mathematically as: \left(x+y\right)^n=\sum_{k=0}^n{n\choose k}y^k\,x^{n-k} Now suppose that we have the following mathematical expression: \sum_{k=0}^{n}{n\choose k}\,(-1)^k if we substitute x=1 and y=-1 in the first...
  47. G

    Prob. for average value or less in binomial distribution?

    Hello! Is there a closed form expression or a good estimate for the probability that a binomial distribution yield the average np or less. Basically I'm asking for a good way to evaluate P=\sum_{k=0}^{np} \begin{pmatrix} n\\ k \end{pmatrix} p^k(1-p)^{n-k} I just figured that for the...
  48. M

    Calculate x^33 Coefficient: Binomial Theorem

    use the binomial theorem to determine the coefficient of x^33 in the expansion of (\frac{1}{4}-2x^3)^17 ive played around with it and come up with 33^C_17 as a coefficient.am i right in saying that is all the question asks Homework Equations The Attempt at a Solution
  49. U

    How To apply Binomial Therem For, Z = 0 and Z R

    Hi Friends Please Solve my problem Please TEll Properly dq = Surface Charge da = Surface Area Radius of ring = w Total Radius = R qo = Point Charge Distance from Center of Ring to Point Charge = Z I want to know how I ca apply binomial theorem to solve the equation If Z = 0...
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