■
increase in demand for tech
■
growth of devices that depend on internet
○
à new system developed with 128 binary code sequences
●
Permutations
○
Permutations
– the number of different ways in which objects can be arranged in
order
■
Number of permutations of n objects selected at X time can be found by
Ni! ¸ (NX)!
■
Ex: 3! = (3) • (2) • (1) = 6
■
Can be found on calculator easily
○
Selecting Some (NOT all) Objects in a Group
■
Ex: 12 players on a team, how many diff ways can 5 players be selected?

Use formula [ N! ¸ (N – X)! ]
■
12! ¸ (12 – 5)! à 12! ¸ 7!
●
Combinations
○
Combinations
– the number of different ways in which objects can be arranged
without regard to order
■
Order doesn’t matter, like in permutations
■
Number of combinations of n objects selected X at a time can be found
by:
N! ¸ [ (N – X)! • X! ]
■
N = total number of objects
■
X = the number of objects to be selected
○
Ex: 5 cards randomly selected from 52card deck. How many 5card
combinations exist?
■
52! ¸ (52 – 5)!5!
○
Ex: Probability of a flush – 5 cards of the same suit
■
Choose 5 same suit out of 13 same suit cards in a 52card deck
■
13! ¸ (135)!5!
○
Ex: Probability of Winning State Lottery
■
Pick 6 numbers out of a possible 49
■
49! ¸ (496)!6!
○
Probability does not have a memory
■
Selected chances have same probability of being selected again next
time
■
b/c 2 events are independent and have no influence on one another
○
Combinations = useful in business
■
When a product or service is available with different options
●
Permutation & Combination Functions
○
Permutation
■
=PERMUT (N,X)
○
Combination
■
=COMBIN (N,X)
Chapter 5: Discrete Probability Distributions
●
Chapter Intro
○
What is discrete data?
■
Values are typically whole numbers
■
Most situations never involve fractions
■
Counted values
○
Continuous Data
■
Measured
■
Can be any number, even fractions
○
Chapter Review
■
Determining discrete probabilities
■
Discrete probabilities
– probabilities that describe the likelihood that
certain discrete data will occur
■
Example:

Prices of pizzas, percentage of buyers that purchase (probability)

Number of test questions à probability of passing quiz given that you guessed all of them
■
Discrete Probabilities & Business

Forecasting customer demand to plan for staffing & inventory needs

Quantifying risk of producing defective items to provide better control of manufacturing
process

Gauging diff customer satisfaction scores to improve customer service
Ø
5.1 – INTRODUCTION TO DISCRETE PROBABILITY DISTRIBUTIONS
o
Business Experiments to Calculate Probabilities
§
Record number of customers who enter a store each hour during the day

à # customers entered in specific range
§
Randomly select 6 customers who walked into store & count the number who signed new
cell phone contracts

1/6 customers signed new cell phone contracts
§
Request that e/customer checking out of a hotel rate their satisfaction on a scale of 15

You've reached the end of your free preview.
Want to read all 94 pages?
 Fall '12
 Donnelly
 Standard Deviation, Mean