My Math Forum  

Go Back   My Math Forum > College Math Forum > Advanced Statistics

Advanced Statistics Advanced Probability and Statistics Math Forum


Thanks Tree1Thanks
  • 1 Post By romsek
Reply
 
LinkBack Thread Tools Display Modes
April 8th, 2018, 07:31 PM   #1
Newbie
 
Joined: Apr 2018
From: Canada

Posts: 3
Thanks: 0

Function Of Discrete Random Variable

Suppose you are playing a game that costs 8 dollars to play. You flip 10 coins and, for every head, you win 2 dollars. Whats the probability you lose money?

Last edited by Shima; April 8th, 2018 at 07:35 PM.
Shima is offline  
 
April 8th, 2018, 07:59 PM   #2
Senior Member
 
romsek's Avatar
 
Joined: Sep 2015
From: USA

Posts: 2,207
Thanks: 1159

Quote:
Originally Posted by Shima View Post
Suppose you are playing a game that costs 8 dollars to play. You flip 10 coins and, for every head, you win 2 dollars. Whats the probability you lose money?
Assuming we have a fair coin the number of heads that appear

is a binomial random variable with probability mass function

$p[k] = \dbinom{10}{k}\left(\dfrac 1 2\right)^{10} = \dfrac{\dbinom{10}{k}}{1024}$

we can then associate the earnings with each value of $k$

$v[k] = 2k-8$

$P[\text{we lose money}] = P[k < 4] = p[0]+p[1]+p[2]+p[3] = \dfrac{11}{64}$
Thanks from Shima
romsek is online now  
Reply

  My Math Forum > College Math Forum > Advanced Statistics

Tags
discrete, function, random, variable



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Distribution of a Monotonic Function of a Discrete Random Variable John Travolski Probability and Statistics 2 December 9th, 2017 12:08 AM
Expected value of a function of a discrete random variable snoopmt1 Probability and Statistics 1 August 24th, 2017 01:12 AM
Discrete Random Variable Keroro Advanced Statistics 2 August 17th, 2012 02:22 PM
Discrete random variable hoyy1kolko Algebra 1 February 13th, 2011 06:32 AM
Discrete random variable hoyy1kolko Algebra 1 February 13th, 2011 06:08 AM





Copyright © 2018 My Math Forum. All rights reserved.