Answer: 
≈ 708 
Explanation 
Here we have equation as: 
  4 Al + 3 O₂ → 2 Al₂O₃ 
As we know: 
 No of moles = Mass/ Molar mass 
Here, Mass is 375 g and Molar mass is 27 gms, so no. of moles of Al will be: 
 =375 g /27 g/mol 
 = 13.889 mol 
About mole ratio, we can see that for 4 moles of Al , 2 moles of Al2O3 are formed, so for 13.889 moles of Al, 13.889 mol ÷ 2 =6.944 moles of Al₂O₃ will be formed. 
As we know: 
  Mass= No of moles/Molar mass 
 Mass of Al₂O₃ = 6.944 mol × 102 g/mol 
  = 708.288 g 
 708 of Al2O3 will be produced
Hope it helps!