A LAG needs to connect to another LAG. So on the 2824 ports 23 and 24 will need to be in a LAG also.
What is the best way to connect a PowerConnect a 2848 to a 2824 with cooper cables. I think to use 2 cables in the 47/48 and 23/24 ports, but I doesn't now how configure the Dell OpenManage Switch Administrator. 
connect PowerConnect 2848 to 2824