1. Announcement:
05-10-2017
Views:
1,825
Page 51 of 91 First ... 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 ... Last
Threads 3001 to 3060 of 5449

# Forum: Probability

Probability course and homework discussion. Probability distributions. Probability theory, stochastic processes

1. ### Sticky: We only provide homework help to those who show effort

Welcome to Talk Stats Forum. In order to keep homework help effective and efficient, we request all members to abide by these guidelines: 1)...

• Replies: 0
• Views: 30,210
09-30-2005, 09:44 AM
1. ### [Question] "Supermatch" cards problem

Dear everyone, I have a question that i couldn't figure out clearly. Here is it. Here will i write down what i have been done, and please...

• Replies: 1
• Views: 2,318
BGM
10-25-2011, 02:07 AM

need help understanding this question please? the number of lightning strikes on a square kilometer of open ground in a year has mean 6 and standard...

• Replies: 1
• Views: 4,393
10-25-2011, 02:35 AM
3. ### Help with greater than and less than problems

I am looking for help that basically lets me know if I am on the right track with my methods of solving these problems. I have to use Excel. Please...

• Replies: 2
• Views: 2,659
10-25-2011, 02:57 PM
4. ### Confused with the Sampling Distribution of p

Hello all, I really hope that I can get an answer. I've worked the problem out, but I keep going back and forth in my head about the answers....

• Replies: 1
• Views: 2,028
BGM
10-25-2011, 11:29 PM
5. ### Sampling and Estimation (From STPM)

A random sample X1,X2,X3,...,Xn is taken from a normal population with mean "u" and variance 1. Determine the smallest sample size which is required...

• Replies: 4
• Views: 3,514
BGM
10-25-2011, 11:49 PM
6. ### Wheel of lucky problem

Dear everyone, Here is the problem I tried by defining the functions S(a) and C(a), where S(a) denotes the probability of player A winning if...

• Replies: 4
• Views: 2,229
10-26-2011, 11:23 AM
7. ### [Question] Birthday Problem

Here is the problem, I already get the answer, \frac{r}{365 -365(\frac{364}{365})^s} What do you think?

• Replies: 1
• Views: 2,436
10-26-2011, 12:04 PM
8. ### Can someone explain how to solve this simple problem?

Your favorite team is in the World Series. You have assigned a probability of 63% that they will win the championship. Past records indicate that...

• Replies: 5
• Views: 6,168
10-26-2011, 09:10 PM
9. ### Probability question.

suppose i have a population n=90386 where: typeA=46362, typeB=22012, typeC=22012 if i choose 145 items from the population (without returning...

• Replies: 9
• Views: 2,369
10-26-2011, 09:58 PM
10. ### Expected Value Question

Plz help me with this question. I tried but couldn't get the correct answer (Q) A school class of 120 students are driven in 3 buses to a dance...

• Replies: 0
• Views: 3,609
10-27-2011, 04:48 AM
11. ### conditional probability mass function

Is my solution correct (Q) Suppose that p(x, y), the joint probability mass function of X and Y, is given by p(0, 0) = 0.4 p(0, 1) = 0.2 p(1, 0)...

• Replies: 0
• Views: 2,630
10-27-2011, 04:52 AM
12. ### Random Variable

(Q) Suppose that it is known that the number of item produced in a factory during a week is a random variable with mean 50. i) What can be said...

• Replies: 1
• Views: 1,745
10-27-2011, 08:02 AM
13. ### hypergeometric? mean and variance

Consider a group of T persons and let a_1, \ \ldots \ , a_T denote the heights of these T persons. Suppose that n persons are selected from...

• Replies: 3
• Views: 3,435
BGM
10-28-2011, 07:42 AM
14. ### Difficult probability question

Hi - I'm really stuck with this question. I can't find any example quite like it anywhere: Two friends, Ben and Jerry, agree to a random swap of...

• Replies: 5
• Views: 3,267
10-28-2011, 11:42 AM
15. ### Conditional prob question - Is my answer correct

I wondered if someone could confirm my workings... In a certain sports club, 32 % of members play football, 31 % of members play baseball, and 23...

• Replies: 0
• Views: 1,649
10-28-2011, 11:48 AM
16. ### CDF of difference of two independent non-central chi square RVs each 1 d.o.f.

Hi Everyone. I'm glad to have found this forum. This is my first post. I'm interested in obtaining a simple expression (exact or approximate)...

• Replies: 0
• Views: 1,918
rhz
10-28-2011, 02:30 PM
17. ### I have a real world problem and need some guidance in solving it.

Hi, I was hoping someone more knowledgeable than myself might be able to help me out with this. I'd be happy just to be pointed in the right...

• Replies: 0
• Views: 1,735
10-28-2011, 03:08 PM

Please tell me how to solve this question correctly (Q) Buses arrive at a specified stop at 15-minutes intervals starting at 7 a.m. That is, they...

• Replies: 1
• Views: 3,470
Ra0
10-28-2011, 03:18 PM
19. ### marginal and conditional density and probability

Dear all, I really need your help in solving these questions. If X is the amount of money (in dollars) that a salesperson spends on gasoline and...

• Replies: 4
• Views: 3,845
10-29-2011, 03:23 PM
20. ### Help with Excell and 1 2 and 3 Standar Deviations

I was given the following data: 45, 89, 78, 85, 47, 25, 56, 99, 100, 98, 65, 65, 65, 56, 35, 53, 58, 57, 54, 89, 78, 75, 75, 72, 83, 84, 75, 82,...

• Replies: 1
• Views: 2,363
10-29-2011, 05:39 PM
21. ### method of moments and MLE question

Hello all, I have a question regarding a problem asking to obtain an estimator for theta using MLE and method of moments and then to compute the...

• Replies: 7
• Views: 5,618
10-29-2011, 08:48 PM
22. ### Probability 101

Hi from Melbourne. I have a rudimentary probability question that you will probably find amusing but hopefully you can also help me! I am...

• Replies: 2
• Views: 2,119
tom
10-31-2011, 04:16 PM

a point is selected at random from the bounded region in the plane between the curves y=x^2 and y=2-x^2. let X be the x-coordinate, and Y be the...

• Replies: 1
• Views: 2,170
BGM
11-01-2011, 01:30 PM
24. ### probability of winning with every failed attempt

Hello, I am trying to figure out what the probability of "losing" on a task is after every failed attempt, where each time there is no evidence of...

• Replies: 14
• Views: 2,851
BGM
11-01-2011, 01:36 PM
25. ### Indicated probability

What are the steps to arrive at the answer? A bag contains 6 red chips and 11 blue chips. Two chips are selected randomly without replacement from...

• Replies: 1
• Views: 2,259
11-01-2011, 05:32 PM
26. ### Sandbagger

What is the probability of a golfer winning 3 out of 4 golf tournaments? 5 out of 7? 40 players in each tournament, players have USGA handicaps.

• Replies: 4
• Views: 2,190
11-01-2011, 09:45 PM
27. ### Probability model for random variable

I'm stumped on this one! You roll a pair of fair dice. If you get a sum greater than 10 you win $50. If you get a double you win$30. If you get a...

• Replies: 1
• Views: 3,529
BGM
11-02-2011, 03:13 PM
28. ### Multiple Regression Question

..........

• Replies: 1
• Views: 1,785
11-02-2011, 04:52 PM
29. ### Probability Help

Here is the problem: Let X denote the number on a chip drawn at random from an urn containing three chips, numbered 1,2, and 3. Let Y be the...

• Replies: 1
• Views: 2,999
BGM
11-03-2011, 02:04 AM
30. ### Discrete Random Variable Joint Distribution Problem?

Hello, I am really, really stuck on something that probably should be obnoxiously simple. So I have this problem: Suppose X and Y are...

• Replies: 3
• Views: 3,857
BGM
11-03-2011, 04:01 AM
31. ### need help with chebyshev, please

a random variable X has pdf f(x)=(3/2)e^-|3x| -∞ < x < ∞ a. find the mean and variance of X b. use the chebyshev inequality to find a...

• Replies: 1
• Views: 1,732
BGM
11-03-2011, 10:57 AM
32. ### stochastic annual survival rate

Hi all, I want to simulate the trajectories over time of animal populations for which I know the annual survival rate, S, estimated in the field...

• Replies: 0
• Views: 1,753
11-03-2011, 09:41 PM
33. ### Random Variable/Expected Value Problem (Profit)

I thought I'd gotten the hang of these, but then the newer problems had different value types that needed to be used. This particular question asks:...

• Replies: 2
• Views: 5,786
BGM
11-03-2011, 11:57 PM
34. ### Gamma Distribution

This is my question Suppose that X  Ga(n, L). Show that E = (n(n + 1) . . . (n + k − 1))/(L^k) k , for k a positive integer. I know how to...

• Replies: 2
• Views: 3,365
11-04-2011, 07:29 AM
35. ### Exponential Family

Hi! I'm trying to demonstrate that the following distribution is a member of the exponential family. Theta * x^(Theta-1) * exp (-x^Theta) ...

• Replies: 4
• Views: 4,296
11-04-2011, 08:29 AM
36. ### How do I calculate probability using excel?

I have 8 weeks worth of fantasy football scores from 12 different teams in a MS excel spreadsheet. Each team plays a different team every week. Is it...

• Replies: 3
• Views: 4,580
11-04-2011, 12:17 PM
37. ### Probability mass function for binomial random variable

I know that the Probability mass function for binomial random variable includes the "combination" formula as opposed to the "permutation formula". ...

• Replies: 1
• Views: 2,948
Ra0
11-04-2011, 12:46 PM
38. ### Distributive Law P[A u (B n C)]

I am trying to find a synonymous formula formula for: P = P Can anybody help me? I found somewhere that said it was equal to P but I...

• Replies: 4
• Views: 15,705
11-05-2011, 04:07 PM
39. ### Help with an expectation.

How do i determine: E(Y'Xb|X). I think this is the estimated variance covariance matrix but I'm not sure.

• Replies: 3
• Views: 2,909
BGM
11-06-2011, 03:10 PM
40. ### Expectation of random vectors.

Hi there. I'm trying to prove: Cov(X,Y) = E(XY') - E(X)(E(Y))' So i know the cov of 2 random vectors is written by Cov(X,Y) = E can...

• Replies: 9
• Views: 4,996
11-06-2011, 03:27 PM
41. ### 2 questions: Finding the optimal value of the mean of a standard normal distribution.

I have two questions involving the Standard Normal Distribution. The first one involves finding the optimal mean, the second one involves proving...

• Replies: 1
• Views: 2,820
BGM
11-06-2011, 04:02 PM
42. ### Two quick problems:

Hey guys, having a bit of trouble and can't find anyone to double check my work: Mean failure rate of a communication is 1 error per 10 000 000...

• Replies: 12
• Views: 2,632
11-06-2011, 11:37 PM
43. ### formula of parabola

Hi what is formula of parabola? thanks

• Replies: 1
• Views: 2,527
BGM
11-07-2011, 11:19 AM
44. ### maximum of function?

Hi who determine maximum of function? thanks

• Replies: 1
• Views: 2,517
11-07-2011, 11:36 AM
45. ### maximum of parabola

Hi who determine maximum of parabola? thanks

• Replies: 5
• Views: 3,433
11-07-2011, 12:14 PM
46. ### Beating the odds

The mortality tables give person 'A' 5 more years to live. He/she dies after 7. The tables give a person more years to live the longer that...

• Replies: 0
• Views: 1,818
11-07-2011, 12:47 PM
47. ### Sample distribution help!!!

I'm studying for my upcoming stats test and i can't seem to figure out this problem its been bugging me for over an hour now. I thought that i would...

• Replies: 1
• Views: 3,417
BGM
11-08-2011, 01:43 AM
48. ### Confusion with distributions..

I have the following question and I have no idea how to solve it. 3) The population variance of the distribution for X is 100. Two random samples...

• Replies: 6
• Views: 3,293
BGM
11-09-2011, 02:38 AM
49. ### expectation value(s) and gaussian stochastic process

Hi all. I do some calculations including noise described by a random variable \eta\left(t\right) which is gaussian distributed at all instants t ...

• Replies: 3
• Views: 3,545
11-09-2011, 07:00 AM
50. ### Consistent Estimator

I'm new here so i'm not sure what is wrong with my tex (i cant get +)so I will write the correct information under my tex lines A balanced one way...

• Replies: 4
• Views: 6,215
alf
11-09-2011, 11:41 AM
51. ### What is the meaning of kurtosis?

I found in Wikipedia that kurtosis is measurement of peakiness of the famous bell curve. If kurtosis is more than 3, it is kind of peaky, if kurtosis...

• Replies: 10
• Views: 25,175
11-09-2011, 12:39 PM
52. ### probability question

I have a probability question. It also relates to computer networks but I figured I would try posting it here. The question deals with packets...

• Replies: 1
• Views: 3,257
BGM
11-10-2011, 12:55 AM
53. ### statistics of sinc function with normal argument

Hi, Can anyone point me to the pdf, cdf, moments, etc of y = sinc(x) = sin(pi*x)/(pi*x) where x ~ N(0,s^2)? Thanks!

• Replies: 0
• Views: 3,077
rhz
11-10-2011, 01:21 PM
54. ### CDF of difference of chi squared random variables

Hi, I posted this question under "Probability Theory" and got no response. Maybe I'd have better luck here? I'm interested in obtaining a...

• Replies: 1
• Views: 8,611
BGM
11-10-2011, 03:50 PM
55. ### question regarding distribution mean (app Crystal Ball)

Hi everyone, I have a question that I have come across running some Crystal Ball simulations however, I think the problem is rather a generic...

• Replies: 1
• Views: 2,414
BGM
11-11-2011, 05:27 AM
56. ### A two-outcome game on a limited budget: the probability of being busted over n tries

Hello, My question does not regard a piece of homework, but I have become stuck trying to solve a statistical problem and I would really...

• Replies: 2
• Views: 2,195
BGM
11-13-2011, 03:37 AM
57. ### A probability confusion

There are two packs of cards. pack A and pack B. A = {11, 12, 13, 15, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32} B = {11. 13. 15. 21. 22, 35}...

• Replies: 1
• Views: 2,850
BGM
11-14-2011, 12:03 AM
58. ### A problem using Bayes Inference

This is our Master Qualify Exam problem, please help! Thanks! In a large national park, the number of raccoons in a randomly-picked acre is a...

• Replies: 1
• Views: 2,484
BGM
11-14-2011, 12:27 AM
59. ### show that the sum of e(i) = 0 and the sum of e(i)*Yhat(i) = 0

Consider a usual multiple linear regression model: Y = X β + ε where Y is a (n x 1) response vector, X is a (n x p) matrix with its first column...

• Replies: 16
• Views: 14,490
BGM
11-14-2011, 02:40 AM
60. ### joint distribution of f(x,y)

joint distribution f(x,y) = (1/4)xy if 0<x<2, 0<y<2 = 0 otherwise how to find P(XY<2)? I wrote it out as ∫(from 2...

• Replies: 4
• Views: 3,030
11-15-2011, 02:21 AM

Use this control to limit the display of threads to those newer than the specified time frame.

Allows you to choose the data by which the thread list will be sorted.

Note: when sorting by date, 'descending order' will show the newest results first.