Purchase Solution

Discussing the Distribution Theory

Not what you're looking for?

Ask Custom Question

1. Let the random variable X have the pdf
f(x) = 2/sqrt(2(pi)) e^(-x^2/(2) ), 0<x<infinity, zero elsewhere.
Find the mean and the variance of X.
Hint: Compute E(X) directly and E(X^2) by comparing the integral with the integral representing the variance of a random variable that is N(0,1).

2. Compute P(X_1 + 2X_2 - 2X_3 > 7), if X_1, X_2, X_3 are iid with common distribution N(1,4).

3. Let X and Y have a bivariate normal distribution with parameters u1 = 20, u2 = 40, sigma1^2 = 9, sigma2^2 = 4, and p = 0.6. Find the shortest interval for which 0.90 is the conditional probability that Y is in the interval, given that X = 22.

Purchase this Solution

Solution Summary

This solution illustrates how to solve a number of distribution theory problems and the response is enclosed within an attached Word document.

Solution Preview

Solution 1

It is given that,

We have,

Put , then and as x varies from 0 to , u also varies from 0 to .
Thus,

Also,

.
We know that, for a Standard normal random variable U,
That is, (1)
Since the integrand is an even function , and hence (1) becomes ...

Purchase this Solution


Free BrainMass Quizzes
Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.