Lesson 9-2 : Words Associated With Probability

Awesome...I'm so lucky to get the words associated with probaility.

Alright, now let's get to the lesson. It's really all definitions and not nearly as hard as some of the lessons we had beforehand.

In the book, they used a dice rolling experiment so i'll just go along with it...

Random Experiment - The act of doing something .
In the experiment, it would be the act of rolling the dice.

Trial - Each time you do something.
In the experiment, it would be each time you rolled the dice.

Simple Event or Outcome - What you get.
The results of the experiment.

Event - Set of outcomes

Sample Space - All of the possible outcomes.

Probability - Number of outcomes in the event / Number of outcomes in the sample space

Sample Problem
Given an unlimited amount of dimes, quarters, nickles, and pennies. Find how many possible ways there are to get 50 cents if you have to use a dime, quarter, and nickle at least once. Then find the probability that you will have to use 2 or more nickles.

Well first we can find the amount, that we have to use. So if we have to use at least one for all three that means that we must have at least 25+10+5. That equals 40 just so you all know.

Then we find how many different ways we can make 10 cents.
1) We can add 1 dime.
2) We can add 2 nickles.
3) We can add 10 pennies.
4) We can add 5 pennies and 1 nickle.

Now we know that there are 4 possible ways to create 50 cents while using a dime, quarter, and nickle at least once.
We see that the nickle is used at least once in all of them, so we just have to find the events where the nickle is used more than once, which is 2.
Now we put the number of outcomes in the event / number of outcomes in the sample space, which is 2/4 or 1/2.

Answer: 4 possible ways. 1/2 probability that we will use 2 or more nickles.

Wow...this website is basically everything i just typed up...with a lot of examples!
http://www.mathgoodies.com/lessons/vol6/intro_probability.html

Reminder!!! Katie you are our next blogMASTER. have fun. =]

Well people say laughter is the best medicine, and well YouTube has plenty of videos to make us all laugh!!! Hahahaha. Here are two really good ones.
http://youtube.com/watch?v=Z4Y4keqTV6w
http://youtube.com/watch?v=5P6UU6m3cqk