4.3 Binomial Experiments

Independent -  (occurrence of one does not affect the probability of the other)

        Definition of Independent  - pg. 144
 
 

Practice - pg. 151

#1
 
 

#2
 
 

TWO-NESS - BINOMIAL Experiment

        1)  Fixed number of trials

        2)  Trials are each Independent

        3)  Each trial has 2 possible outcomes

        4)  Probabilities are constant for each trial
 

#2

#4

#5

#8
 

Example:  Heart Association claims that only 10% of adults over 30 in the U.S. can pass minimum requirements established by Pres. Physical Fitness Commission.  If 4 adults are randomly selected and given the fitness tests.    Is this a binomial experiment?

Terminology              s - success     and      f - failure
 

        P(s) = p  success on one trial

        P(f) = 1 - p = q   failure on one trial

        n  - number of trials

        x - number of successes

        P(x) = probability of EXACTLY  successes in trials

Binomial Formula 
 
 

        Text Version:

 
 

    Do some examples from heart association above.
 
 
 
 

 
 
 
    Complete a Probability Distribution Table for heart association.
 
   
   
   
   
   
   
  ##Note:  There is Table A-1 in Appendix for certain p and  n values

 We'll use calculator  (Directions pg. 201, or Companion ps 44,45)

Practice:

#14

#16  
 

 

Using table given in text
#18
 
 

#20   
 
 
 

#22 good with several parts
 
 
 
 
 

#24 
 
 

Definitely #26
 
 

Analyze #28
 
 
 
 

Set up only  #30
 
 
 
 

#32
 
 
 

Additional Examples

A survey found that 30% of teenagers received their spending money from part-time jobs.  If 5 teenagers are selected at random, find the probability that at least 3 of them will have part-time jobs.
 
 
 

In random guesses, on 5 question multiple choice, what is the probability of getting EXACTLY 3 correct if each question has 4 multiple choices.
 
 
 
 
 

In a large office building, probability of a defective phone is 0.05.  If a sample of 20 are selected, find the probability
    a)  Exactly 5 are defective
 

    b)  at most 3 are defective
 

    c)  At least 3 are defective
 
 
 
 

10 Question True False, probability pass if random guesses.
 
 

10 - Questions - Sometimes/Always/Never -  Probability pass if random guess.
 
 

10 - Questions - multiple choice of 5, probability pass.
 
 

What if # questions increases?
 

20 Questions - Probability Pass - P(X>12)