I had went to the hospital (Doctor who offer CLL) to take xray, and the doctor said that my femur tibia ratio is Femur: 45cm , Tibia : 36cm, which mean i got a longer femur.

However, the weird thing is that when im comparing my tibia and femur with others who is much taller than me (about 10cm-15cm taller), i found that my tibia length is actually about the same as them and my femur length is visibly shorter than them.

Why will this happens? Btw i am Asian, is the femur tibia percentile apply to Asian too or only for European?
And is the Xray 1to1? If i want to confirm again on the length of my femur, can i just use measuring tape to mesure on the xray?