Portfolio Category: Statistics

Tolerance Factors

The use of curve-fitting or regression can have the additional result of the tolerance factor that defines confidence limits for the best-fit function.  Often this is completed as a second effort following determination of the best-fit function.  The traditional theory involves posing random errors about the data and minimizing deviations either by forming a linear…
Read more

Mean and Standard Deviation

A ‘statistic’ refers to a single number measure of a sample.  Statistics relevant to uncertainty are mean value, total covariance, total deviation, standard covariance and standard deviation.  The formulas needed to calculate these with traditional arithmetic are known.  However, the theory does not present error propagation.   A comprehensive theory should be valid for choices…
Read more

Curve Fitting

Curve fitting is the practical way of converting data to a best-fit function that can be carried forward into other calculations.  The candidate function is a special case of datum that varies with an independent variable.  What is ‘best’ is assessed by minimizing deviation of the data from the local datum.  For example, the linear…
Read more