Monday, April 7, 2008

Scribe Post


Sorry about putting this up a day late everyone! Well yesterday in class we went over the homework Mr.K had assigned us on tuesday. The 4th question that was done on the smartboard had 2 different ways to be solved. There was the long way to approach the question and a short way. I'll tell you how the long way went first. For the long way to solve the question we first had to find the z-score, second after finding the z-score you would use "normalcdf" which can be found on the TI-83 Plus by pressing the "2nd" function button then "VARS" to use the "DISTR" a
nd then "1" to use "normalcdf".

This is the question: A college aptitude test is scaled so that its scores approximate a normal distribution with a mean of 500 and standard deviation of 100.

(a) Find the probability that a student selected at random will score 800 or more points.

Here's how the long way of looking at this question would look like below:

The shorter way is to just simply use normalcdf and input these numbers below:

normalcdf(800,1000, 500, 100) = 0.001349
= 0.13%

The reason why you put put these numbers in one go is because normalcdf would find the z-score while also finding the probability of a student selected at random would score 800 or more points in one go which does the exact same thing as the long way does.

The next question that goes with the last question could also be solved in two ways.

Here's the question.

(b) Find score x,such that 76 percent of the students have a score less than x.

Here's the long way of how to look at this question and solve it.

invnorm(0.76) = 0.7063
= 70.63

Mark = 500 + 70.63 = 570.63

Here's the short way of how to look at this question and solve it.

invnorm(0.76,500,100) = 570.63
X = 570.63

Don't forget to put x = 570.63 because if you don't some people wouldn't know what the number is and thus would have a mark deducted away from you.

That's all that we did for the class we did on Thursday March 27, 2008.


Today for class in 3rd period Mr.Kuropatwa gave us our assignments, quizzes and tests back.
Mr.Kuropatwa then talked about the learning tree with us which led to our project of the semester. The project is to create 4 of our own problems, which you can work with a partner or 2 partners but, if you work with a partner you would have to do 5 problems and 6 problems if you have 2 partners. The project is due sometime in June or so but, for the break Mr.K wants to have the questions by the friday we come back. For this assignment given to us for the break we can copy someone else's problems. The project with the due date in June has to be created from your ideas and from scratch. The site that our project will be posted on is
That's all we did for class on Friday March 28, 2008. We didn't have our 5th period class of the day because of the activity for Spirit week in the afternoon.

Also sorry for the like late scribe everyone-_- Some reason my last post I did on Saturday didn't work and well no one told me it wasn't up until I went to check the site myself. Won't be in class today though, because of an appointment I have.

The next scriber will be.. mercee

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