Stat 5.1

What digits would you assign to the boy and girl example?

- 0-4 for girls - 5-9 for boys

How is probability expressed?

- a value between 0 and 1 - the proportionof times that event happens

What is the law of large numbers?

- if we observe more and more repetitions of any chance process, experimental probability will approach to theoretical

A coulpe plans to have children until they have a girl or until they have four children, whichever comes first. use random digit sto estimate the likelihood that they have a girl. what are the assumptions in this scenario?

- it is equally likely to get a boy or a girl - boy or girl is independent of each other

Is chance behavior predicatble in the short run?

- no - only in the long run

Is 25 repetitions enough to say that our estimate is accurate?

- no, 25 is not enough

What are the 3 different ways to find the probability for an event?

- observe the random phenonmemon many times and record each outcome, thus finding the frequency - develop a probability model and use it to calculate a theoretical answer - use a simulation that imitates what would actually happen with the random phenomenon

what is the myth of the law of averages?

- past outcomes do not influence the likelihood of individual outcomes occurring in the future

What is the myth of short-run regularity?

- you can't make short-run predictions based on probability - there is nothing guaranteeing that you will get 5 heads and 5 tails if you flip a coin

How would you assign digits to represent a person from which 50% are employed, 20% are unemployed and 30% are not in the labor force

0-4 for employed 5-6 for unemployed 7-9 for not in the labor force

How would you assign digits to a person from a group of which 70% are employed?

0-6 for employed 7-9 for unemployed

How would you assign digits to a pereson from a group of which 73% are employed?

0-72 for employed 73-99 for unemployed

Write out a simulation for tossing a coin 10 times and finding the chance of a run of 3 consecutive heads or 3 consecutive tails

1) F we toss a coin 10 times, what is the chance of a run of at least 3 consecutive heads or 3 consecutive tails? 2) Assume head or tail is equally likely, and the tosses are independent of each other 3) Assign odds to heads, and evens to tails 4) Read 10 digits at a time, and record results. do this process 25 times and record results.

What is the procedure for writing out a simulation?

1) state 2) plan 3) do 4) conclude