Skewness-Kurtosis test for normality
------------------------------------


	^sktestdc^ varlist [^=^exp] [^if^ exp] [^in^ range] [^, noa^djust]


For each variable in varlist, ^sktestdc^ presents a test for normality based on
skewness and another based on kurtosis and then combines the two tests for an
overall test statistic.  ^=^exp, if specified, specifies the weight.

Note:  This is a variation on ^sktestd^ as described in STB-sg3.  The test per-
       formed here is baed on

           "A Suggestion for Using Powerful and Informative Tests of Normality"
            by R. B. D'Agostino, A. Belanger, and R. B. D'Agostino, Jr.,
            _American Statistician_, vol. 44 no. 4, pp. 316-321,

but with an empirical adjustment to the overall chi-square statistic and its
P value.  The adjustment is not applied if the ^noadjust^ option is used.

Example follows.

Example
-------
	. ^sktestdc weight mpg^

	                Skewness/Kurtosis tests for Normality
	                                              ------- joint -------
	 Variable |  Pr(Skewness)   Pr(Kurtosis)  adj chi-sq(2)  Pr(Chi-sq)
	----------+--------------------------------------------------------
	   weight |      0.575         0.018            5.73       0.0570
	      mpg |      0.001         0.073           10.97       0.0041

	. ^sktestdc weight mpg, noadjust^

	                Skewness/Kurtosis tests for Normality
	                                              ------- joint -------
	 Variable |  Pr(Skewness)   Pr(Kurtosis)      chi-sq(2)  Pr(Chi-sq)
	----------+--------------------------------------------------------
	   weight |      0.575         0.018            5.92       0.0519
	      mpg |      0.001         0.073           13.13       0.0014

Notice that the adjustment may reduce the joint chi-square statistic making
it less significant than before (it has a higher P value).