DETERMINE IF AN EVENT IS INDEPENDENT OR

DEPENDENT

6.16

*Review of Dependent Events

There are 3 red skittles left in a bag with a total of 20 skittles left in it. The probability that you will get a red one when you reach in is: 3/20.

(Click to make the man eat the candy)

But what are your chances of getting a red one if you reach in again? There are now 19 candies in the bag, and only two are red. The probability is 2/19.

Taking the first candy affected the outcome of the next attempt. The two events are dependent.

Sometimes one event can affect the outcome of another event.

*Review of Independent Events

Now you know that the probability of heads landing up when you flip a coin is 1/2. What is the probability of getting tails if you flip it again?

It is still 1/2.

Flipping heads on one flip and tails on another have nothing to do with each other. They do not affect each other at all!

The two events do not affect each other. They are independent

Dependent

or

Independent?

I complete

ly DEPEND on you!

I am INDEPENDENT!

What I do affects nothing and

nothing affects me!

Example- There are 6 beads in a bag, 3 are red, 2 are yellow and 1 is blue. What is the probability of picking a yellow and without replacing it, next choosing a red??

On your paper, name as independent or dependent and then determine the probability.Remember first outcome multiplied by second outcome.

*The answer Dependent!3/6 is the first outcome and 1/5 is the second outcome. Multiply them together ….3/6 x 1/5 = 3/30 or 1/10, .1, and 10% probability.

F D P

1/10 .1 10%

Example- You throw 2 dice. What is the probability that both are 6's?

On your paper, name as independent or dependent and then determine the probability.Remember first outcome multiplied by second outcome.

*This event is INDEPENDENT because the first roll has nothing to do with the second roll. They are independent.

*There is a one in six chance of rolling a six on dice A and a 1 in six chance of rolling a 6 in dice B.

*1/6 x 1/6 = 1/36 F D P

1/36 .027 2.7 %

*Now it is time to try it on your own.

* Number your paper from 1-5 and make it look like this!

This is a grade!!!

6.16 Probability PPT Practice Name Date(Simplify the fractions) I or D 1.

2.

3.

4.

5.

F D P

F D P

F D P

F D P

F D P

*1. The game show contestant spins a spinner with the letters M, O, N, E, and Y. What is the probability that the spinner will stop on the letter N on the first spin and an O the second spin?

M O

NY

E

*2The names of 6 boys and 9 girls

from your class are put into a hat.

What is the probability that the first two names chosen (without putting the first name back in the hat) will both be boys?

*3A box contains 2 green marbles, 3

blue marbles and 1 silver marble, 2 yellow marbles, and 2 pink marbles. Without looking, what is

the probability that the first two

picked will both be blue?

*4You are about to attack a dragon in

a role playing game. You will throw

two dice, one numbered 1 to 6 and

the other with the letters A through

F. What is the probability that you

will roll the values 3 and E? AB

*5. There are 3 black cats and 2 gray cats in a cage, and none of them want to be in there. The cage door opens briefly and two cats escape. What is the probability that both escaped cats are black?

That’s all Folks!