Can i Run UE4 4.9.2 on the thiscomputer?

GPU:Nvidia GForce GTX 745 - 4GB
CPU:Intel i5-4460 3.2GHZ Haswell
Ram Memory:4GB
OS:Windows 7 x64

If i can run UE4 ,what are the best settings for this computer?

Yes you can. The recommended specs are listed here. I would recommend spending a few bucks and getting another 4GB of RAM and you’ll be good to go.