Tata Motors – DVR

Thanks. May I know how you calculated this ratio.

So, suppose if its reverting to mean which comes to 1.8, Either tata motors stock to rise up to 460 from 425 (CMP DVR 2551.8=460) or Tata motors DVR should correct up to 236 (CMP Tata motors = 425 = 2361.8). But which direction is it going to happen is my question? I sold my DVR shares today and bought TATA motors assuming it will go up to 460 levels. Lets see how it plays out. Would be a good learning.