HMC1010 Log slope and intercept calculation formulas

Hi,

My customers are considering HMC 1010.

I got a question about calculation formula of log slope and interception.

If we use RFBK = 4.7 KΩ, RSHUNT = 2.2 KΩ, and RSET = 24 KΩ when determining β on page 11-22, the calculation result is β = 3.33.
However, it is β = 1.67 in the data sheet.

Where did 1/2 come from?

The HMC 1020 data sheet has the same circuit diagram.
However, the formula for determining β = 1/2 (RFBK / (RFBK // RSHUNT // RSET)))).
Is the formula in HMC 1010 data sheet wrong?

Best regards,

Yuya