Lecture 3

# Lecture 3 - Probability and Statistics in the Life...

This preview shows pages 1–6. Sign up to view the full content.

Probability and Statistics in the Life Sciences (Spring 2010) AMS 110.02 Lecture 3 (chap3) Donghyung Lee

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Section 3.8 Counting (supplement) X-factorial The factorial of a non-negative integer x, denoted by x!, is the product of all positive integers less than or equal to x. Ex1) 5!=? Ex2) 3!/5!=? ! ( 1)( 2) (2)(1) 1! 1 0! 1 x x x x = - - = =
Section 3.8 Counting (supplement) Permutations An ordered collection of distinct elements. The number of r -permutations (each of size r ) from a set S with n elements (size n ) is denoted by When counting groups of times (where the order inside the group changes the group), we use a permutation. ! , ( )! n r n P n r n r = -

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Section 3.8 Counting (supplement) Example How many different ordered arrangements of 2 could be selected from the 3 items A , B , and C ? AB , BA , AC , CA , BC , and CB 6 ordered arrangements are possible! Each arrangement is known as a permutation . 3 2 3! 3 2 1 6 6 (3 2)! 1! 1 P = = = = -
Counting (supplement) Combinations An unordered collection of distinct elements. The number of r -combinations (each of size r ) from a set S with n elements (size n ) is denoted by When counting groups of times (where the order inside the group does not change the group), we use a combination. ! , !( )! n

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/28/2011 for the course AMS 110 taught by Professor N/a during the Spring '08 term at SUNY Stony Brook.

### Page1 / 19

Lecture 3 - Probability and Statistics in the Life...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online