+
+/* T-TEST private data */
+struct t_test_proc
+ {
+ double mean;
+
+ /* Population std. deviation */
+ double std_dev;
+
+ /* Sample std. deviation */
+ double s_std_dev;
+
+ /* count */
+ double n;
+
+ double sum;
+
+ /* Sum of squares */
+ double ssq;
+
+ /* Std Err of Mean */
+ double se_mean;
+
+ /* Sum of differnces */
+ double sum_diff;
+
+ /* Mean of differences */
+ double mean_diff ;
+ };
+
+