April 8th 2009

OK... so today we reviewed a few old concepts and started on some new ones.

FIRST things first...

That, my friends, is the "normal" bell curve. The curve pretty much everything everywhere falls into. But what does it show us exactly?

Lets take a peek at how its devided up...

OK... so between the red lines lies 68% of all data.
between the Green lines lies 95% of all data.
between the Yellow Lines lies 99.7% of all data.

Now what these sections show us is not JUST the % of data within each sections.
Between any two z-scores chosen along the axis of the curve we can find the are, the percentage AND a probability all in one.

On another point, remeber how befor we had to worry about window settings and clearing pictures ans so on jsut to find the ara between two z-scores? Well frett no more. Mr.K showed us the quick-fast way to do it. Get your calculators ready...

STEPS :
-ON
-2nd
-VARS
-2
You will then on your home screen see somthing that looks like "normalcdf( ". At this point, you type in your z-scores (lowest,highest) OR your range, mean then the standard deviation.. in that order , seperated by commas... like so (low end of the range,high end of the range, mean, standard deviation).
-Don't forget to CLOSE the bracket! )

Quick example of the FIRST way using the Z-scores.
Ex 1. Q. Given the Z scores -.2 and 1.4, what percentage of the data lies in that particular range?
A. normalcdf(-.2,1.4)
*hit enter*
The number you get is 0.4985
That number gives you three things.
-The area between those two numbers is .4985
-The percent of data within those two numbers (49.85%)
-The probability that of all the data collected, that something would be "picked" out of that specific section.
What the question asked for was percentage... so your answer would be 49.85%

Next example of the OTHER way by using the range, mean and standard deviation.
Ex 2. Q. A selection of numbers has been aquired. Given a high of 190 and a low of 160, a mean of 150 and a standard deviation of 10, what is the probability that a selected number from a particular group of numbers is within that range?
A. normalcdf(160,190,150,10)
*hit enter*
You get 0.1586

Final thing we used was the Reverse norm function. It is a function we have that allows us to find the z score using the area.
STEPS:
-ON
-2nd
-VARS
-3
At this point you enter in the area/persentage/prabability.

Well that about summs it up. Gnight.
Next scribe is Eugene.

Today's Slides: April 8

Here they are ...

Applied 40S April 8, 2009

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April 07/09 scrib

Hey guys sorry for the late post my relative had gone in to the hospital, so i only got home at 11... Also please bare with me on today's class's scribe because i am not understanding the work very well and am still learning. so anything i have posting that is incorrect please leave a comment so i can correct it which possibly some help

Today we worked with Z-scores and the normal curve

Before we got into it MR.k had given us a Littlee quiz on determining the length of arrowheads one standard deviation below and one above the mean of numbers. Also on knowing what percentage of arrowheads are within one standard deviation of one mean length.

We then corrected the quiz and handed it back

Next we talked about curving marks..



The graph above represents the marks of a large number of students with the mean mark of 69.3% and stranded deviation of 7

so this shows that the students with the marks of 62.3 to 76.3 are the mean marks of the class and are about 68-69 percent are in that mean. as the others shows above.

So knowing this then

68% of the marks are between 62.3-76.3 percent
34 percent are between 69.3 and 76.3 percent
50% are below 69.3%
and 16% are above

So since we have been doing non standerd deviations till this point which means the mean and standard deviation of the distribution or problem have been the standard deviation and mean of the data. now we will try a


standard normal deviation

scale on the x-axis on the window of your calculation is the Z-score(standard score) which is the mean. and standard deviation is 1 so since it is a probability distribution the area under the curve=1
which means it is 100% chance of every score being included in this problem(distribution)

To figure this out on the calculator you press

WINDOW
(then add your y and x numbers along with the xscl etc..)

QUIT

2nd VARS(dist)
(then move to the right to draw)

then press number 1 which is shadenorm

then in the open bracket put in the standard deviation and mean i think

close bracket

ENTER

your graph should be shown..

that's about all we did in class again if anything is in correct please leave a comment and help me correct it because i am unsure of my knowledge of this unit.

I'm trying and hoping to succeed

next scribe is...KATIE

Today's Slides: April 7

Here they are ...

Applied 40S April 7, 2009

View more presentations from dkuropatwa.

Today's Notes

In today's notes, we learn of two ways on how a normal distribution curve is formed. Using the mean and the standard deviation (in other words, z-score) we can form what shape it is. The mean, is the indicator to where the curve is position on a horizontal plane, whilst the standard diviation is indicates how steep the curve is. Depending on the standard diviation, the curve can either become very narrow or very wide. You can determine whether the standard deviation is smaller or larger by the curve's shape. If the curve is narrow, the standard diviation is small, and vice versa when the curve is wide.

We've also have learned of how to interpret a Z-Score. By multiplying the score with the Standard Deviation then adding it with the mean, we reveal the value of the Z-Score itself.

The next Scribe will be either Melissa or Chelsea.

Example(s):
1)












2)
-1 (2) + 6 = 4

Today's Slides: April 6

Here they are ...

Applied 40S April 6, 2009

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Developing Expert Voices: The Assignment

The Assignment
Think back on all the things you have learned so far this semester and create (not copy) four problems that are representative of what you have learned. Provide annotated solutions to the problems; they should be annotated well enough for an interested learner to understand and learn from you. Your problems should demonstrate the upper limit of your understanding of the concepts. (I expect more complex problems from a student with a sophisticated understanding than from a student with just a basic grasp of concepts.) You must also include a brief summary reflection (250 words max) on this process and also a comment on what you have learned so far.

If you wish you may work in groups of two or three students but not more. A group of two students is required to create five problems; a group of three, six problems.

Timeline
You will choose your own due date based on your personal schedule and working habits. The absolute final deadline is June 7, 2009. You shouldn't really choose this date. On the sidebar of the blog is our class Google Calendar. You will choose your deadline and we will add it to the calendar in class. Once the deadline is chosen it is final. You may make it earlier but not later.

Format
Your work must be published as an online presentation. You may do so in any format that you wish using any digital tool(s) that you wish. It may be as simple as an extended scribe post, it may be a video uploaded to YouTube or Google Video, it may be a SlideShare or BubbleShare presentation or even a podcast. The sky is the limit with this. You can find a list of free online tools you can use here. Feel free to mix and match the tools to create something original if you like.

Summary
So, when you are done your presentation should contain:
(a) 4 (or 5, or 6) problems you created. Concepts included should span the content of at least two full units. The idea is for this to be a mathematical sampler of your expertise in mathematics.

(b) Each problem must include a solution with a detailed annotation. The annotation should be written so that an interested learner can learn from you. This is where you take on the role of teacher.

(c) At the end write a brief reflection that includes comments on:

• Why did you choose the concepts you did to create your problem set?
• How do these problems provide an overview of your best mathematical understanding of what you have learned so far?
• Did you learn anything from this assignment? Was it educationally valuable to you? (Be honest with this. If you got nothing out of this assignment then say that, but be specific about what you didn't like and offer a suggestion to improve it in the future.)

Experts always look back at where they have been to improve in the future.

(d) Your presentation must be published online in any format of your choosing on the Developing Expert Voices (2008) blog.
Experts are recognized not just for what they know but for how they demonstrate their expertise in a public forum.

Levels of Achievement
Instead of levels 1-4 (lowest to highest) we will use these descriptors. They better describe what this project is all about.

Novice: A person who is new to the circumstances, work, etc., in which he or she is placed.

Apprentice: To work for an expert to learn a skill or trade.

Journeyperson: Any experienced, competent but routine worker or performer.

Expert: Possessing special skill or knowledge; trained by practice; skillful and skilled.