The Fit Summary Window displays a summary of calculated statistics and test results for all distributions fit to the current data set.
- Formula, or distribution and arguments for the fitted distribution. When a fit is used as input for an @RISK model, this formula corresponds with the distribution function that will be placed in your spreadsheet.
- Parameters, or individual entries for each of the distribution parameter values included in Formula. Shift is any X-value shift that is applied if the input data exceeds the range of the fitted distribution. A shifted distribution is expressed in the form Dist(arg1,arg2…argn) ± Shift, where a sample drawn from the shifted distribution will have the shift amount added to or subtracted from it. For more information on shift factors, see Chapter 2: An Overview of Distribution Fitting.
- Standard Statistics (Minimum, Maximum, Mean, etc.). These entries display the statistics calculated for all fitted distributions and the distribution of the input data.
- Targets identify the probability of achieving a specific outcome or the value associated with any probability level. Target entries have default values (10% through 95%) that you may change if you wish.
Either values or probabilities may be entered into the target area in the Fit Summary window. If a value is entered, the probability of a value occurring that is less than or equal to the entered value is calculated. If a probability is entered, the value in the distribution whose associated cumulative probability equals the entered probability is calculated.
Note: Any target entered in the Fit Summary window is automatically applied to all fitted distributions and the distribution for input data.
For each of the three tests performed (Chi Sq, A-D and K-S) the Fit Summary window displays the information shown on the GOF tab of the Fit Results window. See the Fit Results – Statistics and Goodness of Fit section in this chapter for more information on these statistics.
