Zunkown impeadance caluration of AN-1557

I am FAE in Japanese Distributor.

Our customer plans to use AD5940 and asks to AN--1557.

Page 5 of AN-1557 says the flowing equation.

Zunkown=VzunkownMag / IzunkownMag x Rtia

Figure2-2 uses general Automatic balance bridge method.

Please see the following material about general Automatic balance bridge method.

I think the correct Zunkown equation is the fllowing.

Zunkown=VzunkownMag / Vo x Rtia

Is my understanding correct?

Best regards

Nobuyuki Kokubo