IA Type II -- Population Trends in China

[StaffOfMoonlite]

I know I'm probably the dumbest kid on the planet but I'm so frustrated;

Last year, our stupid teacher gave us the wrong portfolio to do--and most of us got 15+ on it. So finally, after we're all in AP Calculus BC, she gives us the correct portfolio to do, and it's just...so stressful and frustrating to do.

I've read through the posts here, but like I said, I still don't understand:

How are we supposed to

Define all relevant variables and parameters clearly.

If someone could personally help me, I would be forever grateful.

This is the first of my mountain of questions....-______________-'

[intersoul52]

Hey, I'm doing the same portfolio,

What exactly are they referring to when they say trends?

I also do not understand how I am meant to achieve a function that can model the behaviour of the graph..?

Also, I am completely lost when it comes to interpreting K,L and M?

[Bishup]

I've finally sussed the whole thing, just keep at it and you'll get it

[olivebee]

Hello to everybody!

I am nearly finished with this one, only wondering whether it is better to include graphs that show grids or ones that do not. Does that makes any difference whatsoever?

what software are you using for these graphs? I feel completely defeated by winplot. I just have no idea how to use it.

[soloassassin]

I have this portfolio due on monday, however, I can't do it with ti n spire, because it shows me an error that I can't identify while using the quadratic model

linSolve

(system(

1950=(554.8)^(4)*a+(554.8)^(3)*b+(554.8)^(2)*c+554.8*d+e,

1960=(657.5)^(4)*a+(657.5)^(3)*b+(657.5)^(2)*c+657.5*d+e,

1970=(830.7)^(4)*a+(830.7)^(3)*b+(830.7)^(2)*c+830.7*d+e,

1980=(998.9)^(4)*a+(998.9)^(3)*b+(998.9)^(2)*c+998.9*d+e,

1995=(1220.5)^(4)*a+(1220.5)^(3)*b+(1220.5)^(2)*c+1220.5*d+e),{a,b,c,d,e})

and it says, that it's not possible to find a solution, what did I do wrong?

(I copied this directly from the calculator, so if it looks weird, it's for that just notice how I wrote the equations)

why did you do that for? Is it to determine the parameters? Help me.

[x3misswux3]

Hello everyone!

First of all, I wish you wopnderful holidays - I believe that all of us DO really deserve a bit of laziness. )))

I wanted to ask, what kind of 'technology' did you use while estimating and interpreting parameters K, L, M? I've got an idea how to deal with it but it has virtually nothing to do with technology itself and I need some more data (from the Internet sources). Am I going in the right direction? Can anyone give me a hint? I'll be very grateful.

))) Thank you in advance.

Hey, I'm doing the same portfolio,

What exactly are they referring to when they say trends?

I also do not understand how I am meant to achieve a function that can model the behaviour of the graph..?

Also, I am completely lost when it comes to interpreting K,L and M?

For technology, I've been using this program called Geogebra. Its been really helpful. You can plot points and it especially helps you figure out the values of K, L, and M. You can go to the website www.geogebra.org and download it for free

Utilize the sliders for K, L, and M. It took me a while to get used to the program but just mess around with it for a little bit and you'll get the hang of it.

[sbaergen]

Does anybody know what it means when they say interpret K, L, and M in the equation and how to do this? Any help on this would be greatly appreciated as I am TOTALLY STUCK!!!

[SecrethearT_77]

hey, i am stuck with this portfolio as well and have to be done by thursday !

I am confused, what fits better, exponential function, cubic function or a logistic curve?

i tried it with the cubic, but am stuck with finding a,b,c,d am i even on the right track?

thank you in advance

[Airellerouge]

Hey, Im totally stuck as well. I got the assignment on Friday, but have to hand it in already on Wednesday (I was sick but the teacher wouldnt give me an extension).

I only found one parameter of the function - growth rate. What are the others?

I was gonna go with an exponential function but I dont know how to use the growth rate to make the function fit the original one

Also, are we supposed to first discuss more than one functions it could be and then pick one or should we do more than one model function?

And, as we didnt do exponential functions yet, do I have to state that I did research to find this out, when I did?

Thanks, I would really appreciate some help

[hollis]

Yes, go with grids It looks better like this Btw I used the same program and it was very helpful. If you have any problems I can help, since I finnished that portfolio already. I must say that the use of technology was pretty hard, so if you need anything I'm willing to help Good luck

what program do you use?? I'm really stuck Idk how to develop the model function. Can you tell me what I'm supposed to do when its asking to "analytically develop one model function that fits the data points on your graph" than you.

[kirpich]

Hey!

I'm working on this IA right now and I have a couple of questions I hope you guys could help me clear up. For the question: What types of functions could model the behaviour of the graph? I put the data into excel and got a 6th polynomial function to fit the best, however, the cubic function behaves more like a population would (the 6th polynomial drops at the very beginning and then goes up, which a population would not do) therefore the cubic function would be a more correct function to use...Just would like to know if I'm at least heading in the right direction with my thinking

Also, for when it says "analytically develop" does that mean I have to logically explain why it would be the particular function that I chose? (kind of what I did in the first part of my post) Or does it mean something else?

Thanks!!!

[Daniel Inchan Jung]

I'm actually pretty far into the Portfolio despite having it for 3 days. The only thing stopping me from progressing is the parameter of b in ae^-bt. Could anyone decipher what it was? I was thinking on the lines of mortality rate in percent.

Edited November 23, 2010 by Daniel Inchan Jung

[IvyLeague]

Hello to everybody!

I am nearly finished with this one, only wondering whether it is better to include graphs that show grids or ones that do not. Does that makes any difference whatsoever?

Hey! I was wondering what program you used to plot your function. I've been trying to plot my model on a set of axis but Microsoft excel won't let me.

[BBIS]

Hi, I am working on this IA as well. Could you guys may give me an adivce which software I could use for graphig?

Thanks a lot!

[IBdweller]

I suggest Microsoft Excel, and it can give you some model functions and curves...so far I think a 4th degree function (quartic) works the best...still tweaking with results though.

I'm still quite confused about "setting the parameters and defining the variables". Anyone give me a hint of how to do that?

Thanks

[sunny03]

how do you find K, L and M...?

is it using regression or matrices?

[BBIS]

Yes, go with grids It looks better like this Btw I used the same program and it was very helpful. If you have any problems I can help, since I finnished that portfolio already. I must say that the use of technology was pretty hard, so if you need anything I'm willing to help Good luck

Hey. which program did you use?

thanks!

[BBIS]

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??

Hey, so how did you find a,b,c and d? It would be really helpful, because I am really confused..

Thanks!

[Miraine]

I've gotten a graph here and a graph there done but I'm stuck on the very first instruction: "Define all relevant variables and parameters clearly."

What are these parameters? Are they limitations on the domain and range of the graph? Are they vague concepts or do I have to assign variables to them (like K, L and M later on)? Please help.

Some of my classmates have told me parameters are the coefficients of the equation, and I need to find a number for them. I can't make sense of this but they tell me "everyone is doing it" using matrices.

[pujana]

hey guys,

can someone help me with analytically developing model for the population trend china?? I am not getting anything...

I have graphed the population from 1950 to 1995 in using autograph..

thanks