My Math Forum  

Go Back   My Math Forum > High School Math Forum > Probability and Statistics

Probability and Statistics Basic Probability and Statistics Math Forum

LinkBack Thread Tools Display Modes
October 19th, 2015, 05:40 AM   #1
Joined: Oct 2015
From: Australia

Posts: 1
Thanks: 0

Continuous random variable

Hello everbody i was wondering if anyone could help me out today. My question is

The continous random variable X represents the height in centimetres of a Year 12 male student. A teacher estimates that X possesses the density function

f(x) = (348x-x^2-29700)/18432 for 150 =< x =<198
0 elsewhere

(a) By collecting suitable sufficient data, evaluate the accuracy of this teachers estimated model (empirical test).

(b) Using this data to construct an accurate model of the probability density function possessed by X.

Now this is my train of thoughts so far. What i have done is verified that this is a probability density function. This is true because this definite integral = 0. I also found the expected value of X which was (174) and also the variance of X which was (115.19992)

What's confusing me is that how do i use say some data that i will collect soon to evaluate the model. How do you evaluate a model like this? Also, How do you also go about constructing a probability density function.

Lets just use some radom heights just for the sake of me understanding. Take:

166.1 cm
173.5 cm
188.3 cm
180.4 cm
159.0 cm
163.2 cm
184.8 cm
188.8 cm

can anyone help me use these random data to help me out here?
lstevens is offline  
October 19th, 2015, 02:39 PM   #2
Global Moderator
Joined: May 2007

Posts: 6,628
Thanks: 622

Compute the mean and variance of the data and compare with the theory. Also plot the data in histogram form and compare with the theoretic curve.
mathman is offline  

  My Math Forum > High School Math Forum > Probability and Statistics

continuous, random, variable

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Continuous Random Variables Turismo Advanced Statistics 2 May 20th, 2015 10:43 PM
Continuous random variable tayyeb Probability and Statistics 6 March 19th, 2015 12:50 PM
Question regarding continuous random variables Sid Probability and Statistics 2 May 4th, 2014 12:19 AM
probability at a point for a continuous random variable rsashwinkumar Advanced Statistics 3 January 7th, 2013 04:25 PM
Geometry & Continuous Random Variable Distribution fin0c Advanced Statistics 1 January 23rd, 2011 11:43 PM

Copyright © 2018 My Math Forum. All rights reserved.