Standard deviation - statistical aspects of variability, Operation Management

Standard Deviation - Statistical Aspects of Variability

Although the range gives an indication of variability, its value is solely determined by two measurements, the largest and the smallest. A better indication of variability, which takes into account all of the measurements, is the standard deviation. 

At first sight the following expression might seem to be appropriate. 

f1(x1- µ) +f2(x2- µ) +f3(x3- µ) +... / N

Since we're looking for a measure of dispersion about the mean, then the simple one shown above seems to fit the bill, since, by multiplying the class frequency by the 'distance' of the mid-class value from the mean, and dividing by the number of measurements, it finds the average dispersion of the measurements. 

However, because µis the arithmetical mean, some of the difference values will be positive and the others will be negative. When they are added algebraically the result will be close to zero, giving no indication of the variability. 

This problem can be overcome by squaring the difference terms, the resulting value being termed the variance. The most commonly used statistical measure of variability, the standard deviation (σ, sigma), is calculated as the square root of the variance.

2149_Standard Deviation - Statistical Aspects of Variability.png

Posted Date: 3/15/2013 5:33:29 AM | Location : United States







Related Discussions:- Standard deviation - statistical aspects of variability, Assignment Help, Ask Question on Standard deviation - statistical aspects of variability, Get Answer, Expert's Help, Standard deviation - statistical aspects of variability Discussions

Write discussion on Standard deviation - statistical aspects of variability
Your posts are moderated
Related Questions
Leaders and Their Leadership Styles This week you learned about a number of different leadership theories. Choose two of today's leaders listed below and research on their leade

Nielsen ratings are very important to both advertisers and television programmers because the cost of television advertising time is based on this rating. A show's rating is the nu

Layout Homework Problems 6. Avalanche, Inc. is a manufacturer of premium snow skis. The work is a combination of precision machining and skilled craftsmanship. Before completion, s

• Prepare a 3 to 5 page paper discussing what conclusions you can reach on the importance of team preparation and member selection to the "Define" stage, and eventual success of Si

Samantha (Sam), a book dealer, has the following assets: a building worth $155,000, accounts receivable amounting to $32,500 due within the next three months, and $25,000 cash in t

Performance & Productivity Measurement -Theory of Constraint Traditional financial measures of performance have been criticised by Kaplan and Norton (1992) who voiced thei

Activity Sampling - Process Design This is a method of finding the percentage occurrence of a certain activity by statistical sampling and random observation. It is used when

Leadership training and development throughout all levels of the organization. From your experience discuss the importance this component and why? Include examples

Carter Dalton is well on his way to starting a new venture-- Max, Inc. He has projected a need for $350,000 in initial capital. He plans to invest $150,000 himself and either borro

As OB practitioners we know that emotions form preferences before we consciously evaluate those choices and this impacts the quality of the decisions made at the company. The presi