Thank you both very much - those answers were excellent! My headache has disappeared. Also, thank you haruspex for replying to my other posts - I should get you to do my phone interview for me haha
Thanks again!
Nick.
Question is:
"If you roll a fair coin 10 times what is the expected product of number of heads and number of tails?"
Someone answered 25 at at glassdoor.com. My answer would be:
E(k(10-k)) where k is the rv representing the number of heads thrown.
= 10E(k) - E(k^2)
= 10*mean - (var +...
I'm struggling with Bayes' theory. Please consider the following:
Example 1:
Submarine sinks if one missile hits it. Two ships aim at submarine and fire one missile each. Ship 1 shoots missile X1, ship 2 shoots missile X2.
P(X1 hitting = 0.8)
P(X2 hitting = 0.5)
P(X1 and X2 hitting | submarine...
That first question was (apparently) asked in an interview - generally no calculators/computers. I didn't think it was possible to integrate the normal pdf analytically. It is easy to work with the normal pdf when you are working in terms of standard deviations (68-95-99.7 rule). Calculating...
Thanks for the quick reply!
Regarding the first question: Could you come up with that answer without electronic aid? It approaches the normal distribution due to central limit theorem and the mean is 10000 and variance 20000*.5*.5=5000. So I could write the pdf, but I could not do the...
Doing a bit of study for an interview. Came across this question:
"n unbiased coins. What is the probability that half of them exactly are
heads. Answer the question for n= 2, 3, 20000."
My answers would be:
n = 2: p(1h) = 0.5
n = 3: p(1.5h) = 0
n = 20000: p(10000h) = approx. 0 (close...
Hey all.
On Wiki (http://en.wikipedia.org/wiki/Fourier_transform#Properties_of_the_Fourier_transform) they have some really good pictures explaining the Fourier transform - see the introduction section. The Fourier transform is of an exponentially decaying sinusoid - where the sinusoid...
Hey all, I'm working on a derivation at the moment and I'm just wondering how I can write this mathematically. I've attached by current attempt (see attachment).
What I'm trying to say is:
N is an integer and is constrained to an interval of [-a,+a], where a is real.
Is my 'syntax'...
Problem:
A = n by m matrix
x = m by 1 vector
y = n by 1 vector
C = c by m matrix
E = e by m matrix
Alpha, gamma and theta are constants.
norm(Ax-y) = min
subject to:
norm(Cx) = alpha
norm(Ex) = gamma
transpose(Cx)*Ex = (alpha^2)*(gamma^2)*cos(theta)
I read a paper on how to do this with 1...
Hey all. I'm not too sharp on linear algebra. I've done a first year university course on it, but that was a couple years ago & didn't go into much detail. Here is the problem:
Matrix I (n,1).
Matrix N (m,1).
Matrix G (n,m).
Now... I is a column vector of computed "double differences". These...
Hey all. I've written an algorithm to find the Cholesky decomposition of a symmetric, positive-definite matrix (A). I've used the algorithm from: http://en.wikipedia.org/wiki/Cholesky_decomposition#Avoiding_taking_square_roots
Ok here is my question. My current algorithm solves for A = LDLT...
Hey all. I'm going through my textbook at the moment and struggling to figure out something.
Here is the ideal Brayton cycle (same as in my text).
Now I want to find q in, so:
The first law of thermodynamics can be written as (neglecting changes in ke and pe):
h_in - h_out + q_in - q_out +...