My Math Forum  

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

Advanced Statistics Advanced Probability and Statistics Math Forum

LinkBack Thread Tools Display Modes
July 27th, 2013, 08:27 AM   #1
Joined: Jan 2013

Posts: 4
Thanks: 0

Probability and standard deviation

Hi everyone please provide me the solution for the following problems on probability.Also please give me the valid and good explanation for the how you are arriving to the answers.Actually i am not finding good explanation for these problems in the book.

The table below shows the distribution of a group of 40 college students by gender and class.

Sex Sophomore Junior Senior
M 6 10 2
F 10 9 3
If one student is selected from this group ,find the probability that the student chosen is female or sophomore.

If an integer is read-only selected from all two 2-digit integer what is the probability that integer chosen has at least 4 in 10th place or unit place

A random variable Y is normally distributed with a mean of 200 & a standard deviation of 10
Which one is greater I or II
of the event
that the value of
Y is greater than


ragas88 is offline  
July 27th, 2013, 08:55 AM   #2
Senior Member
Joined: Jun 2013
From: London, England

Posts: 1,316
Thanks: 116

Re: Probability and standard deviation

Here's what I would do with Q1.

First, I'd try a simpler question. What is the probably that a student chosen at random is female?

Well, there are 40 students and 22 of them are female, so the probability that one chosen at random is female is 22/40. I hope that makes sense.

So, for Q1, you just have to count how many students meet the criteria of being female or sophomore. Well, you have the 22 females for a start. And, you also have 6 male sophomores. So, there are 28 who meet the criteria. So, the probability in this case is 28/40.
Pero is offline  

  My Math Forum > College Math Forum > Advanced Statistics

deviation, probability, standard

Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Probability Distribution and Standard Deviation EvanJ Advanced Statistics 4 December 23rd, 2013 08:35 AM
Standard deviation milly2012 Advanced Statistics 3 April 29th, 2012 08:21 PM
Standard Deviation peytonn Algebra 1 December 10th, 2011 05:18 PM
Standard deviation VS Mean absolute deviation Axel Algebra 2 April 28th, 2011 03:25 AM
find expected value, standard deviation, and probability jd254 Algebra 0 May 7th, 2009 12:46 AM

Copyright © 2018 My Math Forum. All rights reserved.