Which of the following statements are correct? 
1) Stress Isobar can be prepared using Boussinesq’s stress distribution theory. 
2) Equivalent point load method yields accurate results. 
3) Newmarks’s method relates the vertical stress with the help of influence chart. 
4) Westergaard’s method helps in determination of stress distribution for layered soils. 
Select the correct answer using the codes given below: