Problem of the Day
If I flip a coin 100 times and end up with 65 heads and 35 tails, would you be suspicious of my coin? What would it take for you to be suspicious?
Problem of the Day
Ms. Clark has organized a random drawing for students where 5 lucky students will get to waive their 1st semester finals. The entire student body of RHS is 1000 students. After the drawing, it turns out that 2 of the 5 winners were members of the varsity football team(of which there are 100). Is she playing favorites??????? Design and perform(5 trials will be sufficient) a simulation to support your conclusion.
Chapter 11 Understanding Randomness
­Randomness must have a certain amount of structure to be considered truly random
­random events or outcomes are best viewed in the “long run” as opposed to a few isolated occurrences
­Is the event random?
(we need to have ways to choose things that are actually random)
Pseudorandom‐ness(good enough for our purposes)
‐computers(calculators) can only do what you tell them
(Open new document‐àopen calculator page and type "randint(0,10)" and hit enter 5 mes)
‐Random number tables
hp://www.nist.gov/pml/wmd/pubs/upload/AppenB‐HB133‐05‐Z.pdf
hp://www.cengage.com/resource_uploads/downloads/
0534627943_27463.pdf
I can guess your numbers................
10
9
1
5
4
Praccal Randomness and Building Simulaons
WacArnolds has a selecon of 3 Merry Meal toys. The boy version and girl version of the toy is in 40% of Merry meals each. A $5 ITunes gi card is in the remaining 20%. How many Merry Meals would you expect to buy in order to get both toys and the gi card?
1. Idenfy the component(acon) to be repeated
The component is geng a Merry Meal.
2. Explain how you will model the components outcome(be specific).
Using the digits 0‐9 which are equally likely, the following combinaons will be used to model the components.
0‐3 is a Boy toy
4‐7 is a girl toy
8‐9 are the gi card
3. Explain how you will combine the components to model a trial.
The components(geng a Merry Meal) are repeated unl we get 1 each of boy toy, girl toy, and the gi card.
4. State clearly what the response variable is.
We want to know how many Merry meals(trials) it would take to get all 3 prizes.
5. Run several trials and record your results.
6. Collect and summarize the results of the trials.
Shape, center, and spread are a must. Depending on the queson you are answering, you may want to include more.
7. State your conclusion.
The simulaon suggests that you may need to buy a median of ### Merry Meals to get all 3 prizes.
It could take more, could take less. Center: Median
Spread: Range
Shape:Unimodal/Multimodal, Symmetric/Nonsymmetric
Using a random number table
­All steps are the same except step 5
­will need to adjust number 2 if you have more/
less than 10(100) possibilities(for instance modeling a die roll)
Simulating a Die(2 dice??)
Suppose we are to randomly select three
students from the class to speak at Parents’ Night about the joys of taking AP Stats. How likely
is it we’ll get 2 boys? Design a simulation using a random number table. A company with a large sales staff announces openings for 3 regional manager positions. 22 of the current sales­people apply, 12 men and 10 women. After interviews, it is announced that all 3 positions go to women. The male applicants believe that there is discrimination afoot. Are they right? Design a simulation and run 3 trials.
Readings and Examples: Pgs 255­264
Homework:Pgs 265­267:3­6,11­13,15, 21,31, 27,35