1. Announcement:
05-10-2017
Views:
1,767
Page 7 of 91 First 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 57 ... Last
Threads 361 to 420 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: 30,168
09-30-2005, 09:44 AM
1. ### Properties of discrete random variables

Hello, would some one with more experience mind to confirm or correct me: For discrete random variables I know: E = aE+b and...

• Replies: 4
• Views: 7,115
11-28-2010, 12:37 PM
2. ### How to solve composite function of random variable?

X is a Cauchy random variable (fX(x)=1/pi(x^2 + 1)). Determine fY(y) if Y=g(X) and g(x) is: x-1 x>1/2 ...

• Replies: 1
• Views: 7,107
BGM
09-25-2010, 03:59 AM
3. ### Time Series Analysis

Hello All. I am a new member to this forum. I wish to understand a couple of papers ...

• Replies: 7
• Views: 7,095
04-18-2017, 03:10 PM
4. ### probability problem

Hi, First Thanks in advance. I am current studying distance education and struggle with some probability homework Qs. So glad I found this site. ...

• Replies: 9
• Views: 7,083
03-21-2011, 10:35 PM
5. ### Properties of Sample Proportions

A city council is considering drafting legislation related to the exclusion of renters with children. Since implementation will be expensive, they...

• Replies: 1
• Views: 7,078
11-04-2012, 09:02 AM
6. ### Expectation Operator

I understand the Expectation (and the expectation operator) in a very crude sense. For example, when applied to both discrete or continuous...

• Replies: 2
• Views: 7,067
08-05-2010, 11:49 AM
7. ### HW: Probability of baby gender given ultrasound results

Given the data on 1000 births, determine if an ultrasound is a reliable method for predicting unborn gender: Ultrasound predicted female/Actual...

• Replies: 1
• Views: 7,054
10-02-2011, 09:02 PM
8. ### Erf & Solving for x in the Normal Distribution cdf

The cdf formula for Normal Distribution is: f(x) = 1/2 If mu = 0 and sigma = 200 x square root of 2 then f(x) = 1/2 Since f(x) is a...

• Replies: 3
• Views: 7,032
04-18-2011, 07:07 AM
9. ### Probability in Census

Hey, having some trouble with a problem: The 2000 census allowed each person to choose from a long list of races. That is, in the eyes of the...

• Replies: 4
• Views: 7,022
03-15-2011, 05:25 PM
10. ### r-value > Probability

I have two wrestlers who are going to arm-wrestle. I want to try to predict who will win based on their previous fights against other opponents....

• Replies: 14
• Views: 7,007
08-24-2011, 06:14 AM
11. ### Point Estimation, Bias, and Mean Square Error question

The reading on a voltage meter connected to a test circuit is uniformly distributed over the interval (theta, theta + 1), where theta is the true but...

• Replies: 1
• Views: 7,002
02-12-2012, 02:55 PM
12. ### Joint density function and conditional distribution

Need help for my assignment question. I just can't get the answer for this question after hours of trying. Given the joint density function ...

• Replies: 2
• Views: 6,973
06-01-2009, 01:58 AM
13. ### Probability question in section involving conditonal probability

With probability of 1/6 there are i defective fuses among 1000 fuses (i = 0, 1, 2, 3, 4, 5). If among 100 fuses selected at random, none was...

• Replies: 1
• Views: 6,967
BGM
10-07-2010, 10:42 AM
14. ### How to modify this function to be a probability density function????

f(t)=t^2 (1-t)^2 (u(t)-u(t-1)), where u(t) is the unit step function. SHOULD I INTEGRATE f(t) where i get F(T) AND THEN DIFFERENTIATE F(T) TO GET...

• Replies: 4
• Views: 6,962
09-21-2010, 04:25 PM
15. ### Simple Probability Question... That I Don't Understand

I am attempting to do some online homework but I'm stuck on the very first question. The first bit wasn't too hard to figure out (I merely multiplied...

• Replies: 4
• Views: 6,952
10-04-2009, 08:48 PM
16. ### Markov Chain: Absorbtion Probability and Hitting Time

Hi Suppose i have a markov chain with state (0,1,2,3) whose transition matrix looks like this .25, 0, .5, .25 .2, .2, 0, .6 0, 0, 1, 0 ...

• Replies: 3
• Views: 6,923
BGM
09-15-2010, 07:34 AM
17. ### help with probability questions

HELPPPPPPPPPPPPPPPPPPPPPPPPPP I am struggling with a introductory stats course, and am in need of some free help on some of my questions plse plse...

• Replies: 10
• Views: 6,915
02-05-2006, 10:12 AM
18. ### [SOLVED] Need help with a problem that I THINK requires Bayes Theorem....

For the combined ELISA-Western blot blood test for HIV positive status, the sensitivity is about 0.999 and the specificity os about 0.9999. Consider...

• Replies: 12
• Views: 6,900
01-28-2012, 03:33 PM
19. ### Marginal pdf

let X and Y be random variable with joint pdf fxy(x,y) = (2/5)*(3x+2y) 0<x<1, 0<y<1. b) calculate the marginal distributions for this i did...

• Replies: 3
• Views: 6,895
09-08-2009, 12:35 PM
20. ### Joint cdf/pmf- Multinomial Distribution.

I'll really appreciate if somebody could take time to explain the following question's answer. Suppose that (N1, N2) is multinomial with n=2,...

• Replies: 4
• Views: 6,895
BGM
01-30-2011, 11:41 PM
21. ### Somebody help me please :(

I am unsure how to do this problem. Can somebody please help me. I was shown on my TI-83 how to do problems similar, (binobpdf) so I don't know if I...

• Replies: 1
• Views: 6,878
10-26-2009, 11:39 AM
22. ### poisson distribution help

hey! i am having a hard time understanding this problem. i just need to know how to get started and then i am good from there. here is the...

• Replies: 1
• Views: 6,876
09-28-2008, 12:42 AM
23. ### Expected Value Problem

The heights of all male students in a university have mean 170 centimetres and standard deviation 10 centimetres. Three male students are randomly...

• Replies: 12
• Views: 6,866
10-17-2010, 10:23 PM
24. ### [SOLVED] Correlation between two normal variables ...

Suppose A ~ N (0,a), B ~ N (0,b-a), C = A + B what is the expression for the correlation between A and C?

• Replies: 17
• Views: 6,860
02-04-2012, 11:48 AM
25. ### What is variance of X-bar^2, if X ~ N(theta, sigma^2), sigma is known?

I want to calculate variance of X-bar^2, (mean of X)^2, when Xi ~ Normal(theta, sigma^2) and sigma is known. plz help.

• Replies: 3
• Views: 6,847
10-10-2012, 10:02 AM

Hi everyone, I m new to stats and I m stuck with this two question for 2 hours now...I ll be really appreciate if someone here could show me how to...

• Replies: 2
• Views: 6,846
02-06-2011, 02:17 PM
27. ### Normal/Binomial Distribution question

Hey guys, I was hoping someone could help me out with this question that I've been stuck on for a few days now. "Shorty's muffler advertises...

• Replies: 0
• Views: 6,845
04-06-2009, 02:52 PM
28. ### Describe Sample Space

Suppose you toss a fair coin until you obtain exactly R heads. 1) What is the probability that K tosses are required? 2) Describe your sample space....

• Replies: 2
• Views: 6,818
10-16-2010, 10:27 PM
29. ### need help with a couple questions

1) The US Army requires women's height to be between 58 in. and 80 in. Find the percentage of women meeting that height requirement. Women's heights...

• Replies: 8
• Views: 6,804
12-16-2008, 05:15 PM
30. ### probability of rocket launch failure

hi everyone. My statistics/probability knowledge is unfortunately striving towards zero, therefore I would greatly appreciate any kind of input on...

• Replies: 4
• Views: 6,804
03-03-2011, 10:24 AM
31. ### probability question im having trouble with

1. A system contains 2 identical pumps 1 and 2, if one pump fails the system will still operate however because of the added strain the other pump is...

• Replies: 1
• Views: 6,795
10-24-2008, 07:17 PM
32. ### i need help with normal distribution please

i can't answer this example...can anyone help me asap please.. The diameter of the dot produced by a printer is normally distributed with a mean...

• Replies: 5
• Views: 6,794
01-18-2008, 03:59 PM
33. ### Chess probability of winning

I've gotten into Chess recently with this app on my iphone and its gotten me thinking...has anyone worked with statistical algorithms for chess...

• Replies: 3
• Views: 6,793
01-17-2011, 03:11 PM
34. ### expectation of sums of random variables

Hi I am having trouble solving a homework problem. It says: N people arrive separately to a profeesional dinner. Upon arrival each person looks...

• Replies: 1
• Views: 6,789
11-23-2005, 11:59 AM
35. ### Random Variable Probability HW Help.

I am lost due to the fact that extra information was provided. An investor plans to invest \$50,000 in one of four investments. The return on each...

• Replies: 3
• Views: 6,778
12-07-2006, 07:54 AM
36. ### Counting rules.

Hi, Can someone please explain to me why the answer to this question is as written? Suppose we deal four 13-card bridge hands from an ordinary...

• Replies: 9
• Views: 6,770
09-26-2010, 08:20 PM
37. ### Proof of covariance of a weak stationary stoch. process.

Hey there. I'm having trouble on how to show this is true. Assuming you have a weakly stationary independent increments stochastic process with ...

• Replies: 15
• Views: 6,742
c2q
02-05-2012, 04:22 PM
38. ### Question about mutually exclusive probability

How do i find mutually exclusive probability? it says in my book that if p(A or B) = p(a) + p(b) then the events are mutualy exclusive. Or does it...

• Replies: 14
• Views: 6,739
10-06-2012, 08:19 PM
39. ### Joint density. Help!

Let x and y have the joint density: f(x,y) = 6/7(x+y)^2 for 0<=x<=1 and 0<=y<=1 a.Find the marginal densities of X and Y. . b.By integrating...

• Replies: 1
• Views: 6,735
BGM
01-31-2011, 03:01 AM
40. ### Z-scores & Central Limit Theory

I have been trying to work on my stats for a right long time now. I can't figue out this one question in my textbook. I don't understand or even know...

• Replies: 1
• Views: 6,724
11-05-2010, 08:04 PM
41. ### Upper bound for the probability one random variable will be greater than another

Hi Everyone! Just came across this forum a few weeks ago and have already gotten some great use out of it. Just want to say thanks to all the really...

• Replies: 2
• Views: 6,720
03-07-2010, 11:33 AM
42. ### need help to calculate variance of sales

Hi, I'm trying to calculate numerical value of the variance of sales, and the probability of a sale greater than 6300 cans. but it seems wrong...

• Replies: 14
• Views: 6,715
09-21-2011, 07:18 PM
43. ### Hypergeometric distribution problem

A purchaser receives small lots (N = 25) of a high precision device. She wishes to reject the lot 95% of the time if it contains as many as seven...

• Replies: 8
• Views: 6,683
09-13-2010, 02:49 PM
44. ### confused by normal distributions with variance smaller than 1

Hello, I am currently working with some normal distributions, and got confused by some specific situation where the density function does not look...

• Replies: 5
• Views: 6,665
10-29-2009, 05:30 AM
45. ### Geometric RV

So i have a question... If X is a geometric RV with parameter p (the geometric definition where x=0,1,2,3...) 1. compute the distribution of...

• Replies: 5
• Views: 6,664
12-14-2010, 09:08 PM
46. ### Uniform Distn, Power Function

Let X1 , ... , Xn ∼ Uniform(0, θ) and let Y = max{X1 , ... , Xn }. We want to test H0 : θ = 1/2 versus H1 : θ > 1/2. Suppose we decide to test...

• Replies: 0
• Views: 6,659
11-30-2010, 07:09 PM
47. ### Z tables

Can someone tell me what Z upper and Z lower values are? I am trying to find theoretical parts out of spec. The specifications are -.30 to .30 with...

• Replies: 5
• Views: 6,658
01-12-2006, 12:31 PM
48. ### Probability practise

An electrical system is set up such that power can get from the source to the switch if both parts A and B are working, if part C is working or if...

• Replies: 18
• Views: 6,657
09-21-2010, 04:41 PM
49. ### Will rounding off Standard Deviation Bins cause error on Histogram?

I am creating a Histogram. I have about 100 points of data and I am using MS Excel's Histogram function to create the "Bins". The data points I have...

• Replies: 4
• Views: 6,650
06-30-2010, 11:34 AM
50. ### "Hepatitis" and "Golf" probabilities.

I'm having some trouble with these... A test for Hepatitis A is 98% accurate: if a person has Hepatitis, the test will come out "positive" with...

• Replies: 7
• Views: 6,649
06-01-2008, 06:51 PM
51. ### problem with a Combination rule word problem

I am having a little trouble finding the answer to this word problem If you drew three cards form a standard deck without replacement, what would...

• Replies: 1
• Views: 6,643
11-02-2009, 02:13 PM
52. ### how do I do it?

Statistics is not my strength so I hope you can explain this in really easy terms! I don't even understand what this question wants me to do, let...

• Replies: 3
• Views: 6,635
01-25-2006, 11:22 PM
53. ### maximizing profit given pdf

Here is the problem I came across while studying for the test and need some help: A retail grocer has a daily demand, Y for a certain product sold...

• Replies: 2
• Views: 6,631
10-14-2008, 02:16 PM
54. ### Textbook Problem. Calculate E(Y2/Y1)

Joint Probability Density Function: f(y1, y2) = 1/8 * y1 * e^(-1/2 * (y1 + y2)) where 0 < y1 < infinity and 0 < y2 < infinity (0 otherwise) y1 + y2...

• Replies: 2
• Views: 6,620
10-13-2009, 11:30 AM
55. ### Probability problem

Find the conditional probalilities of the indicated events when two fair dice (one red and one green) are rolled: The sum is 6, given that the...

• Replies: 5
• Views: 6,618
10-02-2011, 05:12 PM
56. ### Probability of a string containing a specific substring

So I've been getting into concepts like the Library of Babel and infinite monkey theorem, and have been trying to work out how to calculate the...

• Replies: 1
• Views: 6,607
01-18-2012, 11:22 AM

Page 7 of 91 First 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 57 ... Last

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.