Probability tree and table

In class today we had to do a tree diagram to solve the answers to Page 168 from 2 to 14. We also kinda learned how to use a table diagram as well.

Here is an example of a tree diagram and a table diagram

Scribe Post for March 9, 2009

Today in math class we started off with the " The Number of the Day ", which was "7839.126". ( Remember it is homework everyday ) After the teacher told us to take notes.

The notes were on: More Probability

The teacher gave us two questions to solve, which were:

QUESTION: P( rolling a prime number ) with a regular die.

ANSWER: P ( rolling a prime number ) = favourable outcomes

-------------------------------

possible outcomes
= 3/6
= 1/2 or 1:2 or 50%
don't forget to simplify it ---^

QUESTION: Find the probability of rolling two 6's in a row with a regular die.

ANSWER: P (rolling two 6's in a row) = favourable outcomes
-------------------------------
possible outcomes

= 1/36 or 1:36 or 2.8%

To solve the question above you need to use the probability tree.

We also had to take down definitions:

Independent events : - the outcome of one event had no effect on the outcome of another event.

Sample space: - all possible outcomes of an experiment.

Tree diagram: - a diagram to organize outcomes

- contains a branch for each possible outcome of an event.

QUESTION: Probability of landing a coin on heads and rolling an odd number
ANSWER: 3/12

(simplify) 1/4 1:4 25% ( to find the answer you need to use a probability tree or a probability table.

For HOMEWORK we had to answer the question:

A) Trudy, Shana, Saira, Kendra, and Tracie are on team A. Jordan, Micheal, Terrance, Sean, and Suni are on team B. Use a diagram to show all the possible outcomes if the coach assigns each person on team B to defend against a player on team A.

B) Write the sample space.

I chose ERIC to do the next blog.

ScribePost for March 3, 2009

Today in math class, we did "Number of the Day" with the number as "7791.692".


Afterwards teacher guy went up to the projector, pushed a button, turned it on, made a noise, and showed us some notes to take down.


The notes were on:




















First we had to take down some words and their definitions.

Outcome - One possible result of a probability experiment.

Favorable Outcome - A successful result in a probability experiment.


Then he gave us an example with some questions.

"The tiles "S, N, O, W," are placed in a bag.

First question: What is the probability of drawing the letter "W" from the bag?

Another way to write that question is P(W)
(P stands for probability)

P(W) =
favorable outcomes
----------------------------
possible outcomes

So then most of us thought, Hmm, 4 letters, and we only want one of the letters so it must be:

P(W) = 1
---
4

Another way of expressing that is
25%
or
1 : 4




Second Question: What is the probability of drawing a S or an O from the bag? P(S or O) =
favorable outcomes
------------------------
possible outcomes

Now you had to think, 4 letters and we want 2 of them so what are the chances of getting them?

It was, of course,:
2 1
-- simplified as --
4 2
50%
2 : 4


P(S or O) = 1 P(S or O) = 50%
-- or
2 P(S or O) = 1 : 2

Third Question: What is the probability of drawing a consonant from the bag?
P(consonant) =
favorable outcomes
----------------------------
possible outcomes

Since in class, like around 10 people don't know what a consonant is so click that link for the definition.

Anyway, if you know what a consonant is, this is easy since there are 3 consonants, "S, N, and W". Three favorable outcomes, and four in total, you should know this by now:

P(consonant) = 3
--
4

Another way to write this is
75%
or
3 : 4


Fourth and last Question for "S.N.O.W.": What is the probability of drawing a "B" from the bag?
P(B) =
favorable outcome
----------------------------
possible outcomes
Really simple if you listened, there are 4 letters, you want to draw "B", but there is no "B", so there is ZERO chance of drawing it. This is not out of 4 because now there are 5 choices:

P(B) - 0
--
5

Another way to write this is
0%
or
0 : 5








After all that stuff, we were given ANOTHER problem.

A bag contains 10 marbles. Show the probability of the following events as a fraction, a ratio, and a percentage.

1. 3 Blue
2. 6 Red
3. 3. Green
   

A. What is the probability of drawing a red marble?
P(red marble)=
favorable outcomes
----------------------------
possible outcomes

There are 6 red marbles, 10 marbles in total, this is obviously 3 over 5 simplified.
3
--
5
or
60%
or
6 : 10

B. What is the probability of selection a red or blue or green marble?

P(R or B or G)
favorable outcomes
----------------------------
possible outcomes

There are ONLY red, blue, and green marbles in this bag so that makes it a 10 out of 10 chance. -.- STEPHANIE -.-
P(R or B or G)
1
--
1
or
100%
or
1 : 1


C. What is the probability of NOT selecting a red?
P(B or G)=
favorable outcomes
----------------------------
possible outcomes

Your trying not to get a red, so you have to find the probability of all the rest of the outcomes. So add up the amount of blues and greens to get your numerator and the total of all the outcomes as your denominator.
P(B or G)=
4 2
-- simplified --
10 5
or
20%
or
4 : 10

Finally its over!


Homework:

Here are the letters you have to work with:

M.O.U.N.T.A.I.N.

A.What is the probability of drawing the letter "N"?

B. What is the probability of drawing a consonant?


C. What is the probability of drawing a letter?


VIDEO WON'T UPLOAD!

I pick Danielle to do the blog :D

ScribePost for February 27, 2009

Today in math class we did "Number of the Day" which was 7298.154.

Afterwards we had a test on algebra which consists of 30 questions. Our test had questions based on pages 398, 399, and 400.

A question from the test were:

Which expression represents four less than five times a number, where the number is represented by the letter n?
a) 4 - 5n b) 4n - 5 c) 5 - 4n d) 5n - 4

And the answer was d) 5n - 4

After we corrected the tests, Mr. Isfeld gave us a balancing act problem.

Here is a video I found about tips for studying.


Thanks for visiting my post! Please leave a comment! I hoped you liked it!
I pick Ronny to do the next scribe post!!!!

ScribePost for Febuary 20, 2009

Today we started of by Number of the day 6918.205, as usual .

Then Mr. Isfeld gave us back our Algebra test from yesterday and told us it was a practice test. So then we corrected it.

*Opposites: Addition-> Subtraction. Multiplication -> Division.

Practice Test.

1. a+5=11
a+5-5=11-5
a=6

2. b-3=7
b-3=3=7+3
b=10

3. c/5=25
5xc/5=25x5
c=125

4. 6d/6=30
d=5


5. 7e+8=29
7e+8-8=29-8
7e/7=21/7
e=3

6. 2f-2=8
2f-2+2=8+2
2f/2=10/2
f=5

7. g/3+2=7
g/3++2=7-2
g/3=5
g/3(3)=5(3)
g=15

8. h/4-3=2
h/4-3+3=2+3
h/4=5
h=20


9. 4x+2+3x=9
7x+2=9
7x+2-2=9-2
x=11

VERIFY

1. a+5=11
6+5=11
11=11

2. b-3=7
10-3=7
7=7

3. c/5=25
125/5=25
25=25

4. 6d=30
6(5)=30
30=30

5. 7e+8=29
7(3)+8=29
21+8=29
29=29

6. 2f-2=8
2(5)-2=8
10-2=8
8=8

7. g/3+2=7
15/3+2=7
5+2=7
7=7

8. h/4-3=2
20/4-3=2
5-3=2
2=2

9. 4x+2+3x=9
4(1)+2+3(1)=9
4+2+3=9
6+3=9
9=9

10. There are two more than twice as many dogs as cats in the vet. If there are six cats, how many dogs are all in the vet? Show all your work including the equation and verify and answer in a sentence .

6 Cats
6x2+2=d
12+2=d
14=d

Verify
6x2+2=d
6x2+2=14
12+12=14
14=14

There are 14 dogs in the vet.

Then when we were done correcting the practice test. He gave us another question like that to answer:
There are 2 more than half as many boys in class as girls. If there are 12 girls. How many boys are there? Show work.

12G/2+2=b
6g+2=b
8=b

Please comment and see how you think of it :) enjoy . I know its not the best :)
I choose GILBERT for the next Scribepost.

ScribePost for Febuary 19, 2009

Today we had to do "Number of the Day" then we had to do a Test on Algebra.

After we finished the test we had to do a balance.

The total was 50.

As you can see we didn't do very much but we still had to do something.

I would put a video,

but my computers not letting me so sorry.

Please comment and i hope you enjoyed it.

I choose Stephanie to do the next Scribepost.

Scribepost for February 18 2009

Today in math class we did Number of the Day which was 5214.897

Then we did some algebra questions.

1. 5 + x =16 2. 4 + x = 9 3. x + 4 = 9

4. x/6 = 3 5. 4 + x =14 6.16 = x +10

7. x + 5 =11 8. 6 + x =15 9. x/5 = 5

10. 10 + x =20 11. x/7 =7 12. 3 + x =15

13. 6x =30 14. x + 9 =21 15. x +7 =7

16. x +4 = 7 17. x + 4 =13 18. x + 4 =10

After that we had to do harder questions.

I choose Telisa to do the next scribepost.