Property Factor; Determination - Mich. Comp. Laws Section 206.116

Sec. 116.

The property factor is a fraction, the numerator of which is the average value of the taxpayer's real and tangible personal property owned or rented and used in this state during the tax period and the denominator of which is the average value of all the taxpayer's real and tangible personal property owned or rented and used during the tax period.