1. noface0711

    Expected value and variance problem

    K,L,M (independent random variables) E(K)=E(L)=c, E(M)=d, V[K]=f, V[L]=V[M]=g E[(MK+L+2M)^2]=? and V(K+L+M) derive variances and covariances ?
  2. A

    [Basic Statistics and Probability] Expected Value

    Not sure if I have my answer right or wrong? Either way the program will not accept my answer (MyOpenMath). Question: Tickets for a raffle cost $13. There were 739 tickets sold. One ticket will be randomly selected as the winner, and that person wins $$1700 and also the person is given back...
  3. A

    Finding the expected value of Y

    Did I use the right function and interval when calculating E(X^2) and E(X)? This problem is different from the problems that I've seen. I'm given two functions, x and 2-x. Usually it's just one function.
  4. T

    Does changing our expected results change what our sample size should be?

    I had this question from a school assignment, and my thinking is no that what we expect does not change what our sample size would be. I know a larger sample size is best, but , For example 1. If we have a Fair 3 sided dice and expect 1, 2, or 3 to have equal probability of coming out, and we...
  5. L

    the expected value and variance

    Hello I'm currently stuck on a statistics problem (pic attached). I think my attempt to solve the second problem (the one regarding variance) is wrong... Can someone please help me? My textbook states that the correct answer to the second is 1456?
  6. W

    expected value and standard deviation of mean

    The expected number of trout fish that an experienced wrangler catches in a single day is 4 and the standard deviation is 1. Betty and Bo are both experienced wranglers. They plan to spend 5 days fishing. What is the expected value and standard deviation of the mean number of fish that they will...
  7. L

    Expected Value and Variance of a summation of correlated sample means

    Let $\gamma_i$ be constants and $f(\gamma_i)$ be normally distributed random variables. More specifically, $f(\gamma_i)$ is the sample mean of the population $\gamma_i$. Now I have a sum of the $f(\gamma_i)$ given by: \begin{equation} I = \frac{1}{2} \sum_{i=2}^{N} \left( \gamma_{i} -...
  8. K

    What formulas to apply here

    My question about this problem is not so much the arithmetic, but determining what type of problem this is, and what formulas to apply. Any help would be greatly appreciated. A pile of lumber of 55 boards consists of 34 oak boards and 21 walnut boards. 16 of these boards will be randomly...
  9. P

    expected value in year 2020

    Calculate the expected value in year 2020: Given Year 1950 1960 1970 1980 1990 2000 2010 Energy 103 155 243 317 380 432 552 By using Langrange interpolation and assuming years 1950 to 2010 as 1,2,3,4,5,6,7 I get the function as In this I have taken...
  10. F

    Finding out Expected Value

    After being all out for 58 and 78 in two matches in the most prestigious tournament in the world, the coach of a certain national cricket team was very upset. He decided to make the batsmen practice a lot. But he was wondering how to make them practice, because the possibility of getting out...
  11. B

    Expected value of a cardinality

    Dear all, It's about expected value of a cardinality. Any proof or suggestions are appreciated.Thank you all. The question follows. Consider a set \(I\) consists of \(N\) incidents. \[I=\{i_{1},i_{2},...,i_{k},...i_{N}\}\] Each incident has a probability to happen, i.e. incident \(i_{k}\)...
  12. D

    CHI square independent test (small expected frequency)

    the expected frequency for the age of (21-30, 31-36, more than or equal to 37) for operation is less than 5 , so combination of these numbers are required for the expected frequency to be more than or equal to 5 . my question is which numbers should i combine? in the solution, i combine the...
  13. L

    probability question involving PMF and expected value

    Imagine that you are trapped in a circular room with three doors symmetrically placed around the perimeter. You are told by a mysterious voice that one doorleads to the outside after a 2-h trip through a maze. However, the other two doors lead to mazes that terminate back in the room after a 2-h...
  14. I

    Expected value and variance problem- help me pls

    K,L,M (independent random variables) E(K)=E(L)=c, E(M)=d, V[K]=f, V[L]=V[M]=g E[(MK+L+2M)^2]=? and V(K+L+M) derive variances and covariances?
  15. P

    Expected value of an order statistic

    "Find the expected value of the first order statistic Y1 of a continuous uniform distribution." All I know here is that I need to use $f(x) = \frac{1}{\beta - \alpha}$ to find E(Y1). Do I just go all the way back to the definition of expected value??
  16. K

    Complicated expected value

    Hi everyone, I have a problem in caltulating an expected value: E(X+Y+Z)^2(X-Y+1)^2, where X,Y,Z are independend standard normal random variables. I've tried to multiply out brakets and use linearity of expected value, but even then I don't know how to calculate e.g. E(X^3Y). Does someone have...
  17. M

    Expected value of S&P 500

    Compute the expected value of Log S_n+1/Sn, where Sn denoted the value of S&P500 at time n . Using u=1.0063 and d=.993738. The answer should be in terms of p and q. Using Historical prices of the here. Use this estimate to compute p and q.
  18. R

    Poisson Distribution Problem

    Assume that when the German plays Hungary in soccer, each team scores independently as a homogeneous Poisson process with rates λGermany = 1 and λHungary = 3 goals per game. a) Expected number of total goals in a single game. b) Expected number of total goals scored in the first half, given...
  19. R

    Poisson Distribution Problem

    Sorry, disregard. I put this in wrong thread.
  20. M

    Expected Value

    Can someone show the solution to this? The hypotenuse, Y , of the isosceles right triangle shown is a random variable having a uniform pdf over the interval [6, 10]. Calculate the expected value of the triangle’s area.