Purchase Solution

Joint and marginal probability mass functions in coin toss

Not what you're looking for?

Ask Custom Question

A fair coin is tossed four times and X is number of heads on first three tosses and Y on last three. What is the joint probability mass function of x and y? What is the marginal pmf? Are X and Y independent?

Purchase this Solution

Solution Summary

How to calculate the joint probability density function of non-independent events in a coin toss?

How to calculate marginal density function from joint density function?

Solution Preview

A fair coin is tossed four times and X is number of heads on first three tosses and Y on last three. What is the joint probability mass function of x and y? What is the marginal pmf? Are X and Y independent?

The joint mass function can be calculated as follows.

The chance of heads in a toss = 0.5

The chance of k heads in first 3 tosses = C(3, k) x 0.5^3

where C(3, k) means 3 choose k = 3!/[k!(3-k)!] where ! means factorial.

If k = 0,

Probability(X = 0, Y ...

Purchase this Solution


Free BrainMass Quizzes
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.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

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.

Measures of Central Tendency

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