Theoretical Probability Feb23/09 , Dr Eviatar

Well i was posted scribe for Friday but that was our test day.

So...
Today Dr. Eviatar went over last class on probability mentioning the questions on pennies. The Internet was done today's class so she couldn't show us a website she had planned but we got work done anyway!

Today we looked at Theoretical probability

Difference between Theoretical Probability and Experimental Probability

Experimental Probability is when a experiment is needed to show the Probability of something occurring. Such as how many times you will get head on a coin after 25 flips.

Theoretical Probability is a stated fact. Such as having a 50 percent change of either having a boy or a girl.

Our main question looked at was..

In a family of 3 children what is the probability that tow of the children will be girls?

It is a fact that you can have hundreds of children of a certain gender and it will not effect the probability of getting a 50 % (1/2) chance of getting a boy or a girl next.

BBB
BBG
BGB
BGG
GBG
GGB
GBB
BGG



The red text is the only three outcomes of the
diagram at left that shows two girls out of three
children


There are eight outcomes and only three have tow girls out of three children.

So the probability of having two girls in a family with three children is 3/8

We also learned about
Binomial experiments.

Binomial experiments are experiments that has only two possibilities such as flipping a coin there is only

1. heads
2. tails

Towards the end of class Dr Eviatar allowed us to do questions from the homework, and gone over it.

okay that is all that went on in class today! next scribe is!!!!!.......Carmel!

p.s. sorry for the late post i just got off work!