Im having trouble solving this word problem i get stuck after i set up the values but i dont know what im supposed to do next... can anyone help me?

Im having trouble solving this word problem i get stuck after i set up the values but i dont know what im supposed to do next... can anyone help me?

To estimate the number of trout in Big Bear Lake, a sample of 48 were captured and tagged. After releasing them, a net captured 300 trout of which 9 were tagged. What would be a good estimate for the number of trout in Big Bear Lake?