IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => IGCSE/ GCSE => Math => Topic started by: Fouad93 on May 18, 2009, 07:34:47 am

Title: help in iterpolation plz!!
Post by: Fouad93 on May 18, 2009, 07:34:47 am
want help in interplation
Title: Re: help in iterpolation plz!!
Post by: sweetsh on May 18, 2009, 07:35:26 am
What is this?
Title: Re: help in iterpolation plz!!
Post by: Fouad93 on May 18, 2009, 07:36:41 am
its a process to find the median!!
want help
Title: Re: help in iterpolation plz!!
Post by: Fouad93 on May 18, 2009, 07:40:51 am
come on gys no one noes what interpolation means i want some oe to explain it for me!!!!!!
Title: Re: help in iterpolation plz!!
Post by: godfather93 on May 18, 2009, 07:41:47 am
interpolation is the extraction of data from the curve drawn and extrapolation is the extraction of data from outside the curve.
Title: Re: help in iterpolation plz!!
Post by: sweetsh on May 18, 2009, 07:43:13 am
Fouad they usually tell you to find the mean, you find the midpoints and then mutliply each midpoint with the frequency. Then divide by the sum of the frequencies
Example/: MJ07
q6. b) Midpoint find it for the 1st one (0+0.5)/2 =0.25
                                                                  0.75
                                                                  1.25
                                                                  1.75
                                                                  2.25
                                                                  2.75
                                                                 3.25
                                                                  3.75
then you do this ( (0.25*8)+(0.75*27)+(1.25*45)+(1.75*50)+(2.25*39)+(2.75*21)+(3.25*7)+(3.75*3) ) / (8+27+45+50+39+21+7+3)

=1.73
Title: Re: help in iterpolation plz!!
Post by: Fouad93 on May 18, 2009, 07:45:28 am
so ur saying that interporation is finding the mean!!!
Title: Re: help in iterpolation plz!!
Post by: astarmathsandphysics on May 18, 2009, 07:47:03 am
Interpolation is when divide 2 xodinates in a certain ratio to get the other odinate. For example suppose you have (2,6) and (8,3) and you want to find the y ordinate corresponding to x=3. 3 divides 2-8 in ratio 1:5 so divide 6-3 in ratio 1:5 and since the line is down subract your answer from the 6.
Title: Re: help in iterpolation plz!!
Post by: godfather93 on May 18, 2009, 07:47:43 am
interpolation is not finding the mean. Finding the median is part of interpolation becuase you are reading the values of the curve.
Title: Re: help in iterpolation plz!!
Post by: astarmathsandphysics on May 18, 2009, 07:49:15 am
Interpolation is when divide 2 xodinates in a certain ratio to get the other odinate. For example suppose you have (2,6) and (8,3) and you want to find the y ordinate corresponding to x=3. 3 divides 2-8 in ratio 1:5 so divide 6-3 in ratio 1:5 and since the line is down subract your answer from the 6.

I get 3/6=0.5 so the y ordinate =6-0.5=5.5
Title: Re: help in iterpolation plz!!
Post by: sweetsh on May 18, 2009, 07:49:26 am
I  didnt answer about the interpolation thing, he asked about the mean and I answered