В ходе анализа ученые сделали заклю

В ходе анализа ученые сделали заключение о том, что в первой группе средний набранный вес составил 6,5 кг.

Results (English) 1:

The scientists have concluded that, in the first group the average gained weight was 6.5 kg.

Results (English) 2:

During the analysis, scientists have concluded that in the first group, the mean gain weight was 6.5 kg.

Results (English) 3:

In the course of the analysis scientists made conclusion that in the first group the average dialed weight amounted to 6.5 kg).