  A sample of 286 gamma-ray bursts (GRBs) detected by the Swift satellite and
358 GRBs detected by the RHESSI satellite are studied statistically. Previously
published articles, based on the BATSE GRB Catalog, claimed the existence of an
intermediate subgroup of GRBs with respect to duration. We use the statistical
chi^2 test and the F-test to compare the number of GRB subgroups in our
databases with the earlier BATSE results. Similarly to the BATSE database, the
short and long subgroups are well detected in the Swift and RHESSI data.
However, contrary to the BATSE data, we have not found a statistically
significant intermediate subgroup in either Swift or RHESSI data.
