IA Type II -- Population Trends in China

[Awesome Sauce]

I am just wondering what type of graph did you do in the first part of it, as in linear/sin or whatever??

and also i thought parameters were like m=gradient and c=y-intercept or stuff like hat and the constraints arew x>0 and y>0 or something like this??

thanks

try cubic and use matrices

If any one needs help with this task, I finished it last term, so just ask

Got 19/20 points on it.

i got 17. close enough. HIGH FIVE!

[shreya.]

hey people,

i am stuck with the type 2 portfolio.. the population of china one.

i get linear and log as the correct equations but the graphs for polynomial 5 and 6 are more appropriate! what are you guys getting?

Please help! im stuck!

If any one needs help with this task, I finished it last term, so just ask

Got 19/20 points on it, so thats AWESOME

I could use some help as well, what function did u use, i was thinking of using wither an exponential (so that the graph never goes below zero) or the cubic (cause if fits great with the points), but i have no friken idea how to find a,b,c,d (in a ax^3 + bx^2 + cx + d) or a,b (for ae^bx) analitically... any idea??

Try Matrices, that's the easiest way to do it. How do you interpret K, L and M ?

MATRIX.... how do you do it using a matrix..could anybody please tell! Im atuck!

I am just wondering what type of graph did you do in the first part of it, as in linear/sin or whatever??

and also i thought parameters were like m=gradient and c=y-intercept or stuff like hat and the constraints arew x>0 and y>0 or something like this??

thanks

try cubic and use matrices

If any one needs help with this task, I finished it last term, so just ask

Got 19/20 points on it.

i got 17. close enough. HIGH FIVE!

Hey are you sure th cubic function will give values close to the original data and how do u use matrices????

[rabias93]

I'm in the process of working on my internal and i'm not too sure about how I would develop one model function for my graph. I decided that out of an exponential function and a logistic curve I would use the exponential function but I don't know how to come up with the equation any suggestions for what I should do?

[shreya.]

I'm in the process of working on my internal and i'm not too sure about how I would develop one model function for my graph. I decided that out of an exponential function and a logistic curve I would use the exponential function but I don't know how to come up with the equation any suggestions for what I should do?

you can use excel to make the graphs and in that just right click and add trendline.. select the exponential function and chose display equation.. you get the equation.

[Lighthero44]

I tried using a 10x10 matrix so that it would go through all the points. Unfortunately, when doing rref on my calculator, the last row wouldn't show up. Is there something I'm doing wrong or is it the calculator?

[Austin Glau]

I tried using a 10x10 matrix so that it would go through all the points. Unfortunately, when doing rref on my calculator, the last row wouldn't show up. Is there something I'm doing wrong or is it the calculator?

It might help if you say what calculator model you posses.

[HrtlssShn]

Okie. So I have done the graphing and I found that exponential and logarithmic functions work best for modeling the behavior of the graph. When I graphed both the exponential and logarithmic equations they both seemed to fit the data of the original graph. The problem I'm having is choosing which one to use and elaborate on it. Like how exactly would I analytically develop the model. Btw I used excel to come up with my equations.

[rabias93]

Okie. So I have done the graphing and I found that exponential and logarithmic functions work best for modeling the behavior of the graph. When I graphed both the exponential and logarithmic equations they both seemed to fit the data of the original graph. The problem I'm having is choosing which one to use and elaborate on it. Like how exactly would I analytically develop the model. Btw I used excel to come up with my equations.

Hi there I am having trouble with the same issue... if someone could help it would be greatly appreciated

[Conchita medusei]

Hello

Can anybody please tell me if I am going on the right path?

I am using matrices, and then regressions to find the coefficients of KLM.

I think that the cubic function will be the most appropriate, based on my results.

I am a little bit lost.. thank you for your help

[Lighthero44]

I am using a Ti-84 silver edition. Also a friend of mine told me to use transverse matrices, does anyone know how to use those?

[***boom***]

hello, how do you get the parameters of K, L , M. I looked at the pdf posted on the first page but I am still confused o how to get the Parameters.. can someone please help me?

p.s What is regression??

[HrtlssShn]

hello, how do you get the parameters of K, L , M. I looked at the pdf posted on the first page but I am still confused o how to get the Parameters.. can someone please help me?

p.s What is regression??

Hey. If you have a GDC like TI-83 or TI-84 this should be easy. Go to STATS then then click on edit and enter all the data that was given. The years are too large and makes it harder to graph so you can input 0,5,10,15,20,25,30,35,40,45. These are the exact intervals as the years so the accuracy is fine. After you enter both the year and population value quit and then go back to STATS. Go across to CALC then scroll down all the way to logistic...which is B I believe then press enter then put L1 and L2. Then waalaa you have your parameters.

[The00ghost]

hello, how do you get the parameters of K, L , M. I looked at the pdf posted on the first page but I am still confused o how to get the Parameters.. can someone please help me?

p.s What is regression??

Hey. If you have a GDC like TI-83 or TI-84 this should be easy. Go to STATS then then click on edit and enter all the data that was given. The years are too large and makes it harder to graph so you can input 0,5,10,15,20,25,30,35,40,45. These are the exact intervals as the years so the accuracy is fine. After you enter both the year and population value quit and then go back to STATS. Go across to CALC then scroll down all the way to logistic...which is B I believe then press enter then put L1 and L2. Then waalaa you have your parameters.

well, isn't it depending on which function you use? because i get like y,a,b,c...so what are these letters for?

thanks

Edited October 25, 2010 by Mahuta ♥
Please do not use text speak on here-Maha :)

[deissi]

hello, how do you get the parameters of K, L , M. I looked at the pdf posted on the first page but I am still confused o how to get the Parameters.. can someone please help me?

p.s What is regression??

Are you confused about the parameters K, L, and M or what the term 'parameters' refers to? Often times people have difficulties finding out what the parameters are when they are uncertain of what's meant by a parameter. Unfortunately I don't know this task at all, so I'm not able to help you with the parameters in this case, but I can tell you what is meant by parameters in general. Finding the parameters is like defining what you are actually researching in your project - for all I know, K could be anything. Therefore, you will have to define K in the context of your task at hand. Is K the population of China? The rate at which population grows in China? The same naturally goes for L and M.

A good way to know what you have to define and how well you have to explain things is to think about you when you started pre-IB/10th grade. You have to write the portfolio in a way that is comprehensive to you as a 10th grader. Sure, you can't explain matrix computations, but in that case you need to have enough visible steps for that 10th grader to follow what's going on.

Regression means drawing a curve through certain points that you know. You can use your calculator's regression tool to draw a curve that goes through all the given data points and use that to find the nth data point.

P.S. If you knew this stuff already, sorry for the lecture. It might be useful to someone else, though!

[HrtlssShn]

hello, how do you get the parameters of K, L , M. I looked at the pdf posted on the first page but I am still confused o how to get the Parameters.. can someone please help me?

p.s What is regression??

Hey. If you have a GDC like TI-83 or TI-84 this should be easy. Go to STATS then then click on edit and enter all the data that was given. The years are too large and makes it harder to graph so you can input 0,5,10,15,20,25,30,35,40,45. These are the exact intervals as the years so the accuracy is fine. After you enter both the year and population value quit and then go back to STATS. Go across to CALC then scroll down all the way to logistic...which is B I believe then press enter then put L1 and L2. Then waalaa you have your parameters.

well, isn't it depending on which function you use? because i get like y,a,b,c...so what are these letters for?

thanks

The y, a, b, c represent the different letters for the researcher's model. If you look at an original logistic function that should be able to help you figure out which letter from the calculator matches the letter from the model. For example, C would represent K. Hope this helped you.

[chri144]

If any one needs help with this task, I finished it last term, so just ask

Got 19/20 points on it.

19/20 is incredible!

how did you get full marks for technology?? could you let me now what kind of applications you use...?

thank youuu!

[Austin Glau]

For almost all of my portfolios, i used winplot, which is a free application on the web. google it.

To get full technology marks, you just have to show your proficiency with the technology by using it efficiently with your paper. i forget the exact wording of the guideline, but i got full marks for technology i think just by using Mathtype(also counts as technology i think), graphs from winpot, etc.

[haris14]

Based on my knowledge of population growth it will probably not be a linear model. An exponential graph might be useful, or maybe a modification of a logarithmic curve... the best hint I can give you is that if you plot it in excel, and select a trendline, then you can actually test out several types of models - linear, polynomial (from 2nd to 6th order), logarithmic, and probably something else I'm forgetting. I found this to be an invaluable tool!

What did you mean by invaluable tool? Is it not reliable?

Hey all, my task II is due in 3 days, I tried to discover K, L and M but i couldn't !!!

any help or hint and i'll be grateful ?

You can easily get the values for K, L and M with regression (on your GDC).

How can I use regression on my GDC?

[seaniemet]

when you guys make the equation for the function what number are you putting in for time? Because you obviously don't want to put in t as 1950 for example in the equation.

[The00ghost]

when you guys make the equation for the function what number are you putting in for time? Because you obviously don't want to put in t as 1950 for example in the equation.

well then you put for example 0,5,10...etc or 50,55, 60..etc it is up to you

good luck:)