Basic Analysis and Graphing - SAS

58 Performing Univariate Analysis Chapter 2
Fit Distributions
Related Information
• “Statistical Details for Discrete Fit Distributions” on page 81
• “Statistical Details for Fitted Quantiles” on page 84
• “Statistical Details for Fit Distribution Options” on page 84
Fit Distribution Options
Each fitted distribution report has a red triangle menu that contains additional options.
Table 2.16 Description of Fit Distribution Options
Diagnostic Plot
Density Curve
Goodness of Fit
Fix Parameters
Quantiles
Set Spec Limits for K Sigma
Spec Limits
Save Fitted Quantiles
Creates a quantile or a probability plot. See “Diagnostic Plot” on
page 59.
Uses the estimated parameters of the distribution to overlay a density
curve on the histogram.
Computes the goodness of fit test for the fitted distribution. See
“Goodness of Fit” on page 60.
Enables you to fix parameters and re-estimate the non-fixed
parameters. An Adequacy LR (likelihood ratio) Test report also
appears, which tests your new parameters to determine whether they
fit the data.
Returns the un scaled and un centered quantiles for the specific lower
probability values that you specify.
Use this option when you do not know the specification limits for a
process and you want to use its distribution as a guideline for setting
specification limits.
Usually specification limits are derived using engineering
considerations. If there are no engineering considerations, and if the
data represents a trusted benchmark (well behaved process), then
quantiles from a fitted distribution are often used to help set
specification limits. See “Statistical Details for Fit Distribution
Options” on page 84.
Computes generalizations of the standard capability indices, based on
the specification limits and target you specify. See “Spec Limits” on
page 61.
Saves the fitted quantile values as a new column in the current data
table. See “Statistical Details for Fitted Quantiles” on page 84.