Leverage - Countdown Widget (300x250)

HW-
P=.8-true proportion
n=4-number of people polled
Find p(0), P(1), P(2), p(3), p(4)
Use nCr p^r(1-P)^(n-r)
Then use new formulas to find mean and standard deviation

Agenda-

• Went over HW
• People did #2 all parts on board (Mr. M told us we can't use parts of girls only whole girls)
• Go over HW 10 groups went up to board
• Adolfredo got an award and we got candy
• Did HW 11

Notes-
Mean of probability distribution-

=sum of Prob(all diff events)(Value of event)

Standard Deviation-



Announcements-
POW Due Wednesday

Next scribe is Christiana

Linear Interpolation 11.03.08

Today we learned how to do a different way of computing numbers that aren't on the "z table".

Notes:
Figure out how to compute whats going on at the point 1.65.




We know the z table values for both points 1.6 and 1.7.




With knowing those points, we use them to determine the value of 1.65

In this picture above, you can see the points 1.6 and 1.7 on the curve as well as the point we want to know. We connected the two known points with a straight line, which is the same as the point found between the two points on the curve.

z table values:

1.6 = 0.8904

1.7 = 0.9109

Now we take these two points z table values to compute the value for 1.65 as follows:

(0.8904 + 0.9109) / 2 = 1.8013 / 2 = 0.90065 -----> z value for 1.65

"This technique will work to find most points not on the z table" - Mr. Marchetti

Things done in class:

1. learned about linear interpolation
2. go over HW9
3. Classwork: A Normal Poll
4. Mean and Standard Deviation of Probability Distribution

Homework:

1. POW Revisions
2. Quiz on Wednesday (up through HW7)
3. Homework 10 (just introductory) and Read pg 410 both due on Thursday
4. POW: The Knights Switches due November 10

Next Scribe: Drew

Standard deviations and binomial distributions (11-04-08)

Today we mainly focused on binomial distributions and how to determine the values of Z on the table. For example, we worked on homework 9 and Mr. Marchetti explained how to find the "gaps in the table." Basically, if we want to find the number between Z=1.3 and Z=1.4, there is 1/3 of difference between them. Then we determine the value by getting the difference between the values of Z=1.3 and Z=1.4. Then we divided the difference by .33.
After discussing homework 9, we talked about "A Normal Poll," Alex explained how to find the probability that Harriet's poll will show Henry as the winner by using a standard distribution table. Since the true proportion was .6 and the standard deviation .069, we used ratios to get the probability. Alex moved the decimal point of sigma two places to the right, so he used the following equation: 1/6.9=x/10, after cross multiplying, x=1.45. He used the table as a reference to get the value of 1.45 SD from the mean. The value was 82.5, then he divided 82.5 by 2 and added the result to 50, this was equal to 92%.
Then Mr. Marchetti returned the graded POWs and announced that POW 10 will be due next Friday. There is no homework for tomorrow, but there's a quiz on standard distributions and binomial probabilities tomorrow.

The Circus (Oct 31/Halloween!)

We talked about our halloween costumes for a small while at the beginning of class. 

Next we did 'Back to the Circus' pg 402... this was about a circus woman who wanted to stop really close to a wall on a bike. She wants to know when to put the brakes on and she wants to hit the wall only 5 % of the time. to solve this you must use your brain or look below for the answer

100-10 = 90 %

you do this because the normal distribution chart calculates for both sides of the curve so therefore you need to subtract 5% from each side which = 10

look at the chart at 90% and you will see the number SD and estimate the number. I got 1.65 as the SD. Then do a ratio. 

      1 SD  divided by .3 meters = 1.65 SD divided by X meters

this makes X equal .49 and then you add 2 because that is the median and you get to stop at 2.49 meters. 

Also did HW 9 in class but going over those in class tuesday....................... NO HOMEWORK!!! But.... there is a quiz on wed.:

Binomial Probabilities

3 Person Polls

Graph

Normal Distribution

Up to HW 7 

No table stuff

Answer:

Why can we approximate binomial distribution with norm distribution?

Reminder... you can retake end functions with this quiz. 

Next scribe= Marcus P