today in math

HW
Kings switches due 11/10
quiz wednesday
HW 9?

Today we had a wonderful hour and a half of math. Caitlin laughed, Lilli danced, keith sang a song about the heartland. Good times were had by all. Except for Camilla who huddled in a corner and cried like the little dark emo she is. But on a more serious note, let's talk mathematics. And imagine I'm tellin you this with an irish brooch.

Normal Table Page 398

This handy little table lists numbers of standard deviations, starting at zero and increasing by 0.1, and their corresponding area within the standard deviation of the mean. This comes in handy when finding percentages of natural functions that are between one and two deviations.

HW 8 Page 400

Using the natural table, we rationalized ways to find answers to questions similar to those we have done earlier in this unit. The main idea was finding percentages of graphs that lay between 1 and 2 deviations.

Back to the Circus page 402.

A circus stunt girl rides her bike towards a wall and would like to know how close she can start stopping while crashing only 5% of the time.

It was fun. Long live math

(Wednesday) October 29

Today:
Go over homework 6 & 7
More about normal curves

Next Class:
Finish discussing Classwork

Homework:
Quiz next Wednesday
Revisions due Thursday

Homework 6 (393) Means and More in Middletown
1) a) Only 2.5% of the houses cost over $950
b) 68% cost between $500-800
c) 13.5% cost between $350-500
2) 2.5%
3) 84%

Homework 7 (396) Gifts Aren't Always Free
1) The main idea that we are trying to explain to Craig is if the standard deviation was larger the deviation would be broader where as if it was smaller the deviation would be more concise.
2) $29-$24.50 is 68%

Classwork (397) Normal Areas
1) .38
2) .86

Class was the typical short Wednesday. We didn't actually accomplish much, but there was a pretty rad conversation about carrots going on at the next table. For the next class we'll finish where we left off in the Classwork on page 397.

Next Scribe:
Cody Ullrich (for Thursday October 30th)

Tuesday October 28
In Class:
-go over Homework 6
-Graphing Distribution (page 394) activity with TI-nspire

-Normal Areas (page 397)
-The Normal Curve (page 389)

Homework:
-revisions on test due Friday 31
-homework 7
-homework 8
(-there will be a quiz next week on this unit and end behavior. specifics will come later)


Review in Class of Normal Curves:
-68% of data falls inside the first diviation
-95% of data falls inside the second diviation
-2.5% are the sizes of the outer-most sections
(look at previous post by Ann to see pictures of a standard curve)

-if mean changes: the curve will shift to the left or right
-if standard diviation increases: the curve will spread and flatten out
-if standard diviation decreases: the curve will get skinnier and taller


New Information:


Graphing Distributions: (see page 394)

-the total area under the standard curve equals 1 unit
-finding a specific area under the curve gives a probability
-the area under the curve is called integration (or definitive integral)
-the following equation uses the mean and standard diviation to solve for a probablility of a result at any given interval (for example, on a standard curve if you want to find the probability of something happening between points a and b that do not land directly on a standard diviation 'line' you can use this formula to find the probability)

-for the simplest normal curve (a mean of 0 and standard diviation of 1) a simplified version of this formula can be used to find probabilities

(in class we experimented with these equations on the TI-nspire calculators, seeing how the curve changes as the standard deviation and mean get larger and smaller)

Normal Areas: (see page 397)

-this classwork deals with finding percentages of areas between two points, and also finding two points where a certain area would fall. (these problems were done through estimation in class)

The Normal Table: (see page 398)

- We read through this reference section in class and briefly looked at the table of "z number of standard deviations and corresponding area within that section. ("z" is just the value above or below the mean where a certain area is found. z values are equal to the area between 2 points)

Next Scribe: Nicole Anderson! (for Friday October 31)

Scribe Post- October 27- Period 1- Elizabeth C

The first thing we did in class was go over Homework 5. The big ideas for that were:

• As the number of people polled goes up, the percent that was in favor also went up


• The largest bars in the probability graph are the ones closest to the true proportion

Then we learned about the Central Limit Theorem:

Normal Distribution-

• Based on mean and Standard Deviation
• Represents probability of getting a result in an interval
• 68% of results fall within 1 deviation
• 95% will fall within 2 deviations

Inflection Point: The point where the curve switches from Concave up to Concave down.

Continuous Probability Distribution: When every point on the graph has a value(Like a bell curve)

Discrete Probability Distribution: When nothing happens between points (like a bar graph)

After this discussion, we did Deviations of Swinging while Mr. Marchetti checked the rest of the homework (Homework 12, 1, 2, 3 and the rational functions worksheet 380)

After that we whipped out the TI-nspires and did Graphing Distributions

Homework:

1. Revisions Due Thursday
2. Homework 6 and 7

Next Scribe: Kimmy

Friday October 24th

Announcements:

-Handed back World of Functions Test

-Quiz next week on beginning of Pollster's Dillemma

-There will be a section on next quiz that will allow you to retake the End Function's section on the last test. Mr. Marchetti will take your higher score out of the two End Function's sections and will replace your current grade on that section with the better score.

Notes:

We began taking notes on the normal distribution curve, like the one above. This picutre demonstrates the percent each section takes up of the data. The light gray represents 68%, the darker gray combined with the lighter gray represents 95% and all of the shaded portions combined together represent 98% of the data. The +1, -1 etc, demonstrates how many standard deviations that data point is away from the average, which is the middle line.

This picture demonstrates how many standard deviations each point is away from the mean.

Homework

1. Homework 6

2. Test Revision- Due Friday October 31st

Next Scribe Post: Gretchen Stulock

Blog for period 1 October 23th, 2008

Scribe: Taryn M



Agenda:

Go over HW 4

Return Rational Function Quizzes

The Theory Of Polls

Homework Check



We worked on The Theory of Polls and went over it in class. Mr.M only got half of the class done with the homeowrk check and he will do the rest on Monday.



* If you didn't do a good job on the quiz go talk to Mr.M about fixing it! There is a chnace you can retake parts of it.



Homework: Homework 5 and read pages 387-391



next scribe: Lizzy C

Scribe post for Wednesday October 22

October 22:Scribe- Miranda K

Agenda-

• go over hw 2 and 3
• theory of the 3-person poll

HW 3 big ideas:

• for each voter, the probability that the voter is in favor of your candidate is equal to the proportion in favor of your candidate in the overall population.
• if the overall population is big enough compared to the sample size we can approximate polling by sampling with replacement.
• if the population is big enough to justify the sampling with replacement, we need to limit our polling samples to 5%.

theory of 3 person poll is on p. 378. uses nPr and nCr

homework:

• homework 4
• homework check on thurs/mon. he is checking hw 1-3 in pollsters and stuff on end behavior, and inequalities

*scribe for thursday- taryn M.