Standard deviation - sampling decisons, Operation Research

Standard Deviation

The  standard deviation of samples (s) can be estimated by  the pilot  study past studies and the  ranges of distribution. A pilot study  may be  conducted  and the  estimated  standard deviation of the  pilot sample  may be used to determine the size of the sample. The  previous  studies already conducted may  also  prove  to be a  guideline to determine the  sample size. The range of distribution  with the interval in mind the standard devotion may be  calculation of standard  deviation. With  the interval in mind the standard deviation may be  estimated by dividing the  range  by 6 as practically  all values at 99.7 percent  of confidence will  include the mean  ± 3 times  the standard  deviation of the  population. We can illustrate this with  the standard  deviation  of past  studies. If  the standard  deviation s(s)  assumed  to be 60 and the  acceptable error is estimated at ± Rs.10 the sample  size at 95 percent confidence level will be.

                σ x¯ =s/n

                2σ x¯ =10

               5= 60/√n

              σ x¯ = 10/2= 5

              √n = 60/ 5

             n= 144

thus the  sample  size  will include  144 units for 95 percent confidence level with mean  expendture of ± Rs. 10.

                              √n = s/σ x

                            √n= 80/5

                           n= 256

thus the addition  of 112 units will be a useful  an appropriate sample  size  for the  consequent  researcher.

      

      

 

 

 

 

 

Posted Date: 2/26/2013 2:41:45 AM | Location : United States







Related Discussions:- Standard deviation - sampling decisons, Assignment Help, Ask Question on Standard deviation - sampling decisons, Get Answer, Expert's Help, Standard deviation - sampling decisons Discussions

Write discussion on Standard deviation - sampling decisons
Your posts are moderated
Related Questions
A PAPER MILL PRODUCES TWO GRADES OF PAPER VIZ., X AND Y. BECAUSE OF RAW MATERIAL RESTRICTIONS, IT CANNOT PRODUCE MORE THAN 400 TONS OF GRADE X PAPER AND 300 TONS OF GRADE Y PAPER I

These models are used to develop a method to evaluate the merit of alternative courses or action by representing with a mathematical model of the problems where various variab

Seven Step to a Successful Presentation There  are seven  basic  step which  need to  kept  in mind at the  time of  making  a presentation. How  successful one  is at eh end

Area under Standard Normal Curve The graph  of the  standard  normal  curve y = p(z) with  different percentages areas is  shown here. Since p(z) is  a probability  distributi

Support Supporting materials  is vital for  making the presentation effective. It  clarifies the  speaker  ideas  makes  the presentation more  illuminating as well  as intere

Maximize Z = 2x - 7y subject -2x + 3y = 3 4x + 5y >= 10 6x + 7y 4x + 8y >= 5

Solve the following Linear Programming Problem using Simple method. Maximize Z= 3x1 + 2X2 Subject to the constraints: X1+ X2 = 4 X1 - X2 = 2 X1, X2 = 0

#queStudy the case and provide an alternative compensation design, which would redress the problem faced by the two- wheeler major in Chennai.stion..

Word problems based on formulation of linear programming problems. 2.   A manufacturer produces nuts and bolts for industrial machinery. It takes 1 hour of work on machine 1 an