Binomial Definition and 640 Threads

Evaluate sum: $\displaystyle S=\sum_{k=0}^{2n}(-1)^k{2n\choose k}{4n\choose 2k}$

Homework Statement The question requires me to approximate binomial distribution to get poisson distribution. Show that N!/(N-n)!=N^n. Homework Equations N!/n!(N-n)! p^n q^(N-n)=Binomial distribution The Attempt at a Solution I expanded N!/(N-n)! and got...

Homework Statement You are a real estate salesperson and you currently have 10 listings. Past experience has shown that you will sell approximately 70% of your listings. If sales are independent: What is the probability that you make exactly 8 sales? Homework Equations The Attempt...

Wolfram MathWorld states that $$ \sum_{n=1}^{\infty} \frac{1}{n^{3} \binom{2n}{n}} = \frac{ \pi \sqrt{3}}{18} \Big[ \psi_{1} \left(\frac{1}{3} \right) - \psi_{1} \left(\frac{2}{3} \right) \Big]- \frac{4}{3} \zeta(3) $$ where $\psi_{1}(x)$ is the trigamma function. But I can't get my answer in...

Homework Statement Prove that ##\binom{-1}{k}=(-1)^k## The Attempt at a Solution Using induction on ##k##, ##\binom{-1}{0}=1## which is true also for ##(-1)^0=1## Assuming ##\binom{-1}{k}=(-1)^k##, then ##\binom{-1}{k+1}=(-1)^{k+1}## Indeed when ##n=-1##, we can write...

I am looking for a counting interpretation to make the following identity evident: \sum_{k=0}^{n-j}(-1)^k\binom{j-1+k}{j-1}\binom{n}{j+k} = 1 The form of it looks like inclusion-exclusion. The sum is 1, more or less independent of j. So that makes me think it would be something like "how...

I'm having trouble factoring the following binomial... can someone try to point me in the right direction please? 4y^3+4 It has been 7 years since I took algebra and I am trying to get my review done. This one just does not make sense to me right now... Thanks!

We know that the Newton binomial formula is valid for numbers in elementary algebra. Is there an equivalent formula for commuting spherical tensors? If so, how is it? To be specific let us suppose that A and B are two spherical tensors of rank 1 and I want to calculate (A + B)4 and I want...

Hello all! I'm trying to understand whether I can use the binomial distribution in a certain way... According to the equation, to find the probability P of a certain number of successes out of a number you trials, you need the number of trials, n; the number of successes out of the trials...

I highlighted the portion in red in the paint document that I'm not understanding. How can we see by inspection that the product is equal to the series 2?

Homework Statement In a class with 20 and one with 10 students each student has a probability of 0.3 to not show up on a particular day. On a given day, which class is most likely to have the highest ratio of absent students? This was in my exam, unfortunately I did not know how to do it...

Homework Statement Use the binomial theorem to find the coefficient of ##x^6y^3## in ##(3x-2y)^9##. Homework Equations ##1+9+36+84+126+126+84+36+9+1## (I used two lines for the lenght) ##1(3x)^9(-2y)^0+9(3x)^8(-2y)^1+36(3x)^7(-2y)^2+84(3x)^6(-2y)^3+126(3x)^5(-2y)^4##...

Homework Statement Use the binomial theorem to find the coefficient of ##x^8y^5## in ##(x+y)^{13}##. Homework Equations We know 13 - 5 = 8 , so we have ##\binom{n}{5}x^{n-5}y^5 = \binom{13}{5}x^8y^5## ##\binom{13}{5} = \frac{13 \cdot 12 \cdot 11 \cdot 10 \cdot 9 \cdot 8!}{5!8!} = \frac{13...

Homework Statement ##| \ X \in \mathcal P(\{0,1,2,3,4,5,6,7,8,9\}) : |X|= 4 \ | = \ \ ?## Homework Equations There's no wording in the exercise , just what I wrote above.If I understood correctly , they asked me to find the cardinality of the set of all subsets of {0,1,2,3,4,5,6,7,8,9} that...

Homework Statement This one is trickier than the problem in my other thread in my opinion.Twenty-one people are to be divided into two teams , The Red Team and the Blue Team.There will be 10 people on Red Team and 11 people on Blue Team.How many ways to do this? I am not sure how to solve...

Homework Statement A department consists of 5 men and 7 women.From this department you select a committee with 3 men and 2 women.In how many ways can you do this? Homework Equations Since the "overall set" (the entire department) is composed of both men and women and each has a specific...

1. The problem statement Consider the Binomial Distribution in the form P_{N}(m)=\frac{N!}{(\frac{N+m}{2})!(\frac{N-m}{2})!}p^{\frac{N+m}{2}}q^{\frac{N-m}{2}} where p+q=1, m is the independent variable and N is a parameter. Show that it satisfies the marcoff chain...

Is there a way to express ##{n\choose k}{n\choose r}## in another form without n as the "top" of the binomial coefficient? I remember seeing it once but I forgot what it was.

1.Find n, if the term 11 coefficient it is 6 time the term 10 coefficient in 2.(6x^7 + 5x^(-4))^n 3

I quote a question from Yahoo! Answers I have given a link to the topic there so the OP can see my response.

In page 11 of http://math.arizona.edu/~zakharov/BesselFunctions.pdf, I am trying to follow the derivation using binomial theorem to get this step: (e^{j\theta}-e^{-j\theta})^{n+2k}≈\frac{(n+2K)!}{k!(n+k)!}(e^{j\theta})^{n+k}(-e^{-j\theta})^kIf you read the paragraph right above this equation...

The prices for bananes that a fruit shop would have to pay to keep them in stock have a mean of $1.35/kg and a standard deviation of 18 cents. The owner will not pay more than a certain price, but manages to keep stock 8% of the time. What is the maximum price the ownwer will pay? I found...

Greetings to you, Physics Forums regulars! Please allow me to introduce myself a bit first. I'm a student in the Life Sciences, so I don't really have a lot of knowledge on mathematics past the basics. I'm not sure if my problem belongs here. This is my first visit to this...

Here is the question: Here is a link to the question: What are the last three and four terms of (a + b)^n? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

Hi, I am trying to teach myself how to test hypotheses for any distribution, but am having some trouble. X=number chosen each year θ=Mean number chosen in the population H0: θ=.5 h1: θ>.5 The random sample of n=4 is 0,1,3,3 Test the Hypotheses at α≤0.05 assuming X is a...

Random walk or binomial?? Statement: A drunk person wonders aimlessly along a path by going forward 1 step and backward 1 step with equal probabilities of ½. After 10 steps, a) what is the probability that he has moved 2 steps forward? b) What is the probability that he will make it to his...

Hi, I am trying to teach myself how to test hypotheses for any distribution, but am having some trouble. X=number chosen each year θ=Mean number chosen in the population H0: θ=.5 h1: θ>.5 The random sample of n=4 is 0,1,3,3 Test the Hypotheses at α≤0.05 assuming X is a...

Hi, I am new here, and my name is Jonas. I'm a CS major at a university in the Northeast US. I'm a senior and wrapping up degree requirements which include a science track. I chose Chemistry because Physics was full. The chemistry exams are multiple choice (because you couldn't grade 300...

Homework Statement Will someone be kind enough to check my proof (attached) of the following (also attached) theorem?Homework Equations The Attempt at a Solution Oh, and as you might notice, I was beginning to run out of paper, but the binomial coefficients in the bracketed terms obviously...

Homework Statement Use the binomial series to expand the function as a power series. 1/(2+x)3 I have attached an image. I understand until the end of the second line. I don't see the reasoning used to follow through to the third line. the (-1)^n is because the sign alternates becoming...

Find an expression that is identical to \sum_{k=0}^n \binom{3n}{3k} According to Wolfram, the correct solution to this is: \frac{1}{3} \left(2(-1)^n + 8^n\right) But I'm not sure which identities of the binomial coefficient I'm supposed to use to prove this. Can anyone give me some...

Decide constant term in $$\left(3\cdot x^3+\left(\frac{-4}{x} \right) \right)^{20}$$. I have problem with this one, I can't find any example about this one in my book, any advice would be great:)

I'm looking through my statistics notes and on the page that's giving examples of cases where you can use a binomial distribution it gives the problem: "The number of red counters in a randomly chosen sample of 30 counters taken from a large number of counters of which 10% are red." Now...

How many numbers of 6 digits which have exatctly the digit 1 (2 times), digit 2 (2 times), without zero, are there? The book post this solution: \frac{6!}{2!2!}*\binom{7}{2} + \frac{6!}{2!2!2!}*7= 4410, but I'm trying to find an explanation for this result.

Homework Statement Uploaded Homework Equations P(y)=(n c y)p^y(q^(n-y)) this is also uploaded The Attempt at a Solution My attempt at the first two parts is uploaded I am really confused on how to do game 6 and 7. Also I am a bit confused on how what I did worked in P(y=5), as the...

Homework Statement A fair coin is tossed 491 times. The total number of heads or tails is then even or uneven. Is the probability that the head will result in an even result equal to 1/2 Motivate your answer with a strict mathematical proof. Homework Equations I am having some trouble...

Homework Statement Of all the weld failures in a certain assembly, 85% of them occur in the weld metal itself, and the remaining 15% occur in the base metal. A sample of 20 weld failures is examined. a. What is the probability that fewer than four of them are base metal failures...

Use the binomial expansion to give the approximation $\frac{1}{\sqrt{1 - A^2u^2}}\approx 1 + \frac{1}{2}A^2u^2$ How can this be done? Using the definition for (x - y), we have $$ (x - y)^n = \sum_{k = 1}^{n}(-1)^k\binom{n}{k}x^{n - k}y^{k} $$ but $n\notin\mathbb{Z}$.

Hello PF This might be a fairly simple question to most of you, but I was given this problem (don't worry, I already solved it just wondering about something) Suppose the probability of suffering a side effect of a certain flu vaccine is 0.005. If 1000 persons are inoculate, find the...

A pdf is of the exponential family if it can be written $ f(x|\theta)=h(x)c(\theta)exp(\sum_{i=1}^{k}{w_{i}(\theta)t_{i}(x))}$ with $\theta$ a finite parameter vector, $c(\theta)>0$, all functions are over the reals, and only $h(x)$ is possibly constant. I would like to show the binomial...

Homework Statement If a fair die is tossed 7 times what is the probability of at least two 4s? Homework Equations The Attempt at a Solution To solve this I used my TI-84's binomcdf function. I just want to see it I'm doing it correctly. p(2<=x<=7) = 1 - p(0<=x<=1) = 1 -...

I mean the binomial formula is something of the form ##\left(a+b\right)^n## = ##\sum_{i=1}^{n}\dbinom{n}{k}a^{n}b^{n-k}## and then you have the linear map ##\psi : A \rightarrow A## which is a derivation when; ##\theta(xy) = y\theta(x) + x\theta(y)## for all x,y in A so the leibniz formula...

For binomial distributions, how can you tell which central tendency value (mean, median, or mode) and which variability value (interquartile range, variance, standard deviation, etc.) are most appropriate for the data? Thanks for any reply.

Differences between binomial distribution and "forced" probability distribution Hi everyone. Yesterday I was thinking about probability and real life and about the fact that we always expect life's facts to behave according to probability theory. If we flip a coin and we get 6 times heads...

Homework Statement I was given two problems and required to calculate some statistics/parameters for them. They are: 1) The Vancouver Island Marmot is one of Canada’s most endangered species; there are currently only 63 animals left on the Island. To maintain the population, geneticists...

Here is the original question: Here is a link to the original question: What is the third term of the expansion of (2x+y^2)^9? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

1. In scanning electron microscopy photography, a specimen is placed in a vacuum chamber and scanned by an electron beam. Secondary electrons emitted from the specimen are collected by a detector and an image is displayed on a cathode-ray tube. This image is photographed. In the past a 4- ...

Homework Statement prove the following reduction formula, n>0 ∫((1+x^2)^n) dx=(x(1+x^2)^n)(1/(2n+1)) +2n/(2n+1)∫(1+x^2)^(n-1) dx Homework Equations none The Attempt at a Solution one of many attempts, i get close, but no cigar. Huge blow to the calculus ego. Any help would be greatly...

Homework Statement http://i47.tinypic.com/29o3ehc.png Homework Equations (1+x)^n=[1+nx/1!+(n)(n-1)x^2/2!+...+b^n] The Attempt at a Solution here's my attempt to part (i) http://i47.tinypic.com/2yv6y3s.png is it correct?

Homework Statement A committee of 16 persons is selected randomly from a group of 400 people, of whom are 240 are women and 160 are men. Approximate the probability that the committe contains at least 3 women. I just want to know if it's hyper geometric or binomial. I suspect it's hyper...