Recent content by Kalinka35

Obviously the job market is tough for everyone right now, but I was wondering whether anyone might have some guidance for me. I graduated in May 2010 with a B.A. in Math with an Applied concentration from a midwestern liberal arts college. My grades were pretty decent, but I got a few B+'s in...

Okay, never mind I think I got it...

Homework Statement On average one third of seniors at a college will be bring parents to the graduation, one third will bring one parent and the remaining third will not bring any parents. Suppose there are 600 seniors graduating this year. Estimate the probability that more than 650 parents...

Never mind. I think I figured it out.

Homework Statement You are flipping a fair coin n times. Let X be the number of times you get a head followed by a tail (HT) and Y is the number of times you get tail and then a head (TH). Find Var(X) and Var(Y). Homework Equations Cov(X,X) = Var(X) The Attempt at a Solution My...

Homework Statement In a town there are r+1 Republicans and d+1 Democrats. There is a Republican candidate and a Democratic candidate, both of whom will vote for themselves. Aside from them, a Republican voter will vote for a Democrat with probability pRD and a Democrat will vote for a...

Homework Statement Let X be uniformly distributed over [0, 1] and Y be exponentially distributed with λ=1. Assuming X and Y are independent, give the PDF of Z=X/Y. Homework Equations The Attempt at a Solution I know the individual PDFs of X and Y. I was trying to use a geometric...

Well, what I've come up with is that for small dx and dy, the number of houses in that small region, R, is 2000 dxdy. So we essentially want to find the number of residences in R over the total residences in the town. The total residences in the town is known to be 4500 so to find the...

Since there are 2000 houses per square mile, the total number of houses over a certain area would be 2000 time that area. The area would be given by xy. So in this case we have 2000(1.5)(1.5)=4500. Is that what you meant?

Okay, so the number of houses would be given by 2000xy, if I am not mistaken. f_{X,Y}(X=x,Y=y)dxdy isn't clear to me. Wouldn't you need to multiply by 2000?

Homework Statement In a square town that is 1.5 miles by 1.5 miles, the places of residence are uniformly distributed (2000 per square mile) over the whole town. Compute the joint probability density function for the spatial distribution of places of residence (fX, Y). Homework Equations...

Homework Statement The location of an emergency is uniformly distributed over a city district. The district is a square rotated 45 degrees with "radius" r (the distance from the center to the top corner is r). When the emergency occurs, the ambulance is at the center of the district. Let D be...

Ah yes, I understand it now. Thanks very much for your clear explanation.

Hmm, not that I know of. I haven't heard the term convolution before. Could you provide me with a definition?

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...