Jump to content



Photo
- - - - -

Variance.p & Variance.s & Variancea


  • Please log in to reply
5 replies to this topic

#1 Ata.H.D

Ata.H.D

    Newbie

  • Members
  • Pip
  • 17 posts
  • Gender:Male

  • Calculators:
    fx-cp300
    fx-cp400

Posted 08 July 2015 - 11:01 AM

hi

see this

2960ubq.jpg

if I want to calculate Var.P on CP400, what should I do ??


Edited by Ata.H.D, 08 July 2015 - 06:28 PM.


#2 pan.gejt

pan.gejt

    Casio Freak

  • Members
  • PipPipPipPip
  • 131 posts
  • Gender:Male
  • Location:CZ

  • Calculators:
    fx-880, fx-6300G, fx-9700GE, fx-9860G Slim, Classpad 330-A, TI-Nspire + keypad, TI-Nspire CAS, TI-Nspire CX CAS,TI-89 Titanium, HP-50g, SEC-101, fx-991ES PLUS, fx-991DE PLUS, fx-CP400, Canon X MARK I PRO, Citizen SRP-75,

Posted 08 July 2015 - 06:27 PM

Before starting I do some math first. You can compute Var.P by using of 2 methods:

 

1. method

                 Var.P=Var.S*(n-1)/n, Var.S is computed by ClassPad (command variance)

 

2. method

                 Var.P = (sigmax), where sigmax means population standard deviation

               

                similarly

                Var.S = (sx)2 , where sx means sample standard deviation

------------------------------------------------------------------------------------------------------------

 

the 1st method is suitable for list calculation,

 

Var.P = variance(list1)*(dim(list1)-1)/dim(list1), the list1 is used

 

in your case:

Var.S = variance = 27130, n=dim(list1)=5

Var.P = 27130*(5-1)/5

Var.P = 21704

 

the 2nd method is suitable for spreadsheet calculation, because the sigmax is calculated

 

sigmax = 26.0546, computed value

Var.P = sigmax2

Var.P =147.3232 = 21704

 

sx = 164.712, computed value

Var.S = sx2

Var.S =164.7122 = 27130         


  • Ata.H.D likes this

#3 Ata.H.D

Ata.H.D

    Newbie

  • Members
  • Pip
  • 17 posts
  • Gender:Male

  • Calculators:
    fx-cp300
    fx-cp400

Posted 08 July 2015 - 06:38 PM

Before starting I do some math first. You can compute Var.P by using of 2 methods:

 

1. method

                 Var.P=Var.S*(n-1)/n, Var.S is computed by ClassPad (command variance)

 

2. method

                 Var.P = (sigmax), where sigmax means population standard deviation

               

                similarly

                Var.S = (sx)2 , where sx means sample standard deviation

------------------------------------------------------------------------------------------------------------

 

the 1st method is suitable for list calculation,

 

Var.P = variance(list1)*(dim(list1)-1)/dim(list1), the list1 is used

 

in your case:

Var.S = variance = 27130, n=dim(list1)=5

Var.P = 27130*(5-1)/5

Var.P = 21704

 

the 2nd method is suitable for spreadsheet calculation, because the sigmax is calculated

 

sigmax = 26.0546, computed value

Var.P = sigmax2

Var.P =147.3232 = 21704

 

sx = 164.712, computed value

Var.S = sx2

Var.S =164.7122 = 27130         

TanQ

but wich 1 is true??

Eg. I got these on exam!! what should I do??



#4 pan.gejt

pan.gejt

    Casio Freak

  • Members
  • PipPipPipPip
  • 131 posts
  • Gender:Male
  • Location:CZ

  • Calculators:
    fx-880, fx-6300G, fx-9700GE, fx-9860G Slim, Classpad 330-A, TI-Nspire + keypad, TI-Nspire CAS, TI-Nspire CX CAS,TI-89 Titanium, HP-50g, SEC-101, fx-991ES PLUS, fx-991DE PLUS, fx-CP400, Canon X MARK I PRO, Citizen SRP-75,

Posted 08 July 2015 - 07:35 PM

Sorry, I don't understand what you mean : "but which 1 is true??"

Both methods of computation are correct. 

Differences between Population and sample standard deviations

http://libweb.surrey...ter/page_18.htm


  • Ata.H.D likes this

#5 pan.gejt

pan.gejt

    Casio Freak

  • Members
  • PipPipPipPip
  • 131 posts
  • Gender:Male
  • Location:CZ

  • Calculators:
    fx-880, fx-6300G, fx-9700GE, fx-9860G Slim, Classpad 330-A, TI-Nspire + keypad, TI-Nspire CAS, TI-Nspire CX CAS,TI-89 Titanium, HP-50g, SEC-101, fx-991ES PLUS, fx-991DE PLUS, fx-CP400, Canon X MARK I PRO, Citizen SRP-75,

Posted 10 July 2015 - 11:04 AM

It's interesting much cheaper Classwizz computes both values directly

http://abload.de/img...11542228qx0.jpg


  • Ata.H.D likes this

#6 Ata.H.D

Ata.H.D

    Newbie

  • Members
  • Pip
  • 17 posts
  • Gender:Male

  • Calculators:
    fx-cp300
    fx-cp400

Posted 10 July 2015 - 04:03 PM



It's interesting much cheaper Classwizz computes both values directly

http://abload.de/img...11542228qx0.jpg

OMG !!!!

 

hi

after e-mail , I got this

14367938141.jpg


Edited by Ata.H.D, 13 July 2015 - 02:23 PM.





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users