Math

For the discrete random variable X, the probability distribution is given by

P(X=x)= kx x=1,2,3,4,5
=k(10-x) x=6,7,8,9

Find the value of the constant k
E(X)

I am lost , it is the bonus question in my homework on random variables so it must be hard.
Many thanks for any help.

Alicia

  1. 👍 0
  2. 👎 0
  3. 👁 100
asked by Alicia
  1. graph p
    symmetric about x=5 where it is 5k
    suspect zero at x = 0 and x = 10 :)
    k + 2k + 3k + 4k + 5k + k(10-6)+ k(10-7) + k(10-8) + k(10-9) = 1 if that is the whole distribution

    2k + 4k +6k + 8k + 5k = 1
    k = 1/25

    1. 👍 0
    2. 👎 0
    posted by Damon
  2. Thanks a lot. I understood. What is E (X) ?

    1. 👍 0
    2. 👎 0
    posted by Alicia
  3. multiply each x value by its probability (kx)
    E(x) is the sum of them all -- the expected value of x.

    1. 👍 0
    2. 👎 0
    posted by Steve

Respond to this Question

First Name

Your Response

Similar Questions

  1. statistics

    Identify the given item as probability distribution, continuous random variable, or discrete random variable. The amount of time that an individual watches television. a. discrete random variable b. probability distribution c.

    asked by maczindahouse on February 20, 2019
  2. probability

    A random experiment of tossing a die twice is performed. Random variable X on this sample space is defined to be the sum of two numbers turning up on the toss. Find the discrete probability distribution for the random variable X

    asked by padma.c on October 11, 2011
  3. Statistics

    Suppose that the probability distribution of a random variable x can be described by the formula P(x) = x/15 For each of the values x = 1, 2, 3, 4, and 5. For examples, then, p(x=2) = p(2) = 2/15 a Write out the probability

    asked by Chinadoll on October 26, 2009
  4. Stats

    The Geometric distribution is used when we want to find the probability of performing a sequence of trials with X “failures” before the first “success”, where a “success” occurs with some probability p. We can denote

    asked by Becca on September 30, 2013
  5. Statistics

    Suppose that the probability distribution of a random variable x can be described by the formula P(x) = x/15 For each of the values x = 1, 2, 3, 4, and 5. For examples, then, p(x=2) = p(2) = 2/15 a Write out the probability

    asked by Kelly on October 26, 2009
  6. Math

    the question i need help with is: Classify the random variable as finite discrete, infinite discrete or continuous. The random variable given is the number of hours a child watches television on a given day.

    asked by Winnie on June 8, 2011
  7. Statistic

    Jake plays basketball. Assume y= the number of basketball goals that Jake makes during a given season, and assume y can only take values from 0 to 6. The following table represents the probability distribution for the discrete

    asked by Victoria on November 28, 2015
  8. statistics

    two dices are tossed once. let the random variable be t he sum of the up faces on the dice. A). find and graph the probability distribution of the random variable. and b) calculate the mean (or expectation) of this distribution

    asked by sharik on May 22, 2011
  9. Stats

    Assume that the table below represents the distribution of X. Note that X is a discrete random variable. The second column reports the number of observations for each value of X. Based on this information, what is the value of the

    asked by ashley on October 29, 2015
  10. Probability

    MY MAIN PROBLEM IS FIGURING OUT WHAT DISCRETE DISTRIBUTION TO USE, BERNOULLI, BINOMIAL, DISCRETE UNIFORM, GEOMETRIC NEGATIVE BINOMIAL, OR POISSON. Every time I choose one, it's the incorrect one. Is there some way I can easily

    asked by Amelie on March 6, 2008

More Similar Questions