<prompt> At what age upper segment : lower segment ratio becomes 1 : 1 ?3 - 6 years5 - 8 years7 - 10 years10 - 12 years  <response>: AgeUS : LS RatioBirth1.7 : 13 years1.3 : 17 - 10 years1 : 1 10 years0.3 : 1 