A community for students.
Here's the question you clicked on:
 0 viewing
pakinam
 one year ago
A random variable X has the probability distribution
value 1 2 3 4
probability 0.5 0.25 0.125 0.125
(For those of you who are interested, this is the geometric p=0.5 “killed” at 4. X is the number of times I toss a coin if I follow this rule: I’ll toss the coin till I get the first head, but I’ll stop after 4 tosses even if I haven’t got a head by that time.)
1Find E(X)
2Find SE(X)
pakinam
 one year ago
A random variable X has the probability distribution value 1 2 3 4 probability 0.5 0.25 0.125 0.125 (For those of you who are interested, this is the geometric p=0.5 “killed” at 4. X is the number of times I toss a coin if I follow this rule: I’ll toss the coin till I get the first head, but I’ll stop after 4 tosses even if I haven’t got a head by that time.) 1Find E(X) 2Find SE(X)

This Question is Closed

Khlara
 one year ago
Best ResponseYou've already chosen the best response.01)v1*p1+v2*p2+v3*p3+v4*p4

abhi_abhi
 one year ago
Best ResponseYou've already chosen the best response.2\[E(X)=\sum_{i=1}^{n}x _{i}p _{i} = 1*0.5+2*0.25+3*0.125+4*0.125 = 1.875\] \[SE(X)= \sqrt{E(X ^{2})(E(X)})^2\] \[E(X ^{2}) =\sum_{i=1}^{n}x ^{2}_{i}p _{i} = 1^2*0.5+2^2*0.25+3^2*0.125+4^2*0.125 = 4.625\] \[SE(X)=\sqrt{E(X^2)(E(X))^2} = \sqrt{4.625 (1.875)^2} = 1.053268722\]
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.