34 C.F.R. § 222.69
If the real property of an LEA and its generally comparable LEAs consists of one classification of property but the property is assessed at different percentages of true value in the different LEAs, the Secretary determines whether the LEA meets the applicable tax rate requirement under § 222.68(c)(1) by using tax rates computed by—
(b) Performing the computation in paragraph (a) of this section for each of its generally comparable LEAs and determining the average of those computed tax rates.
(Authority: 20 U.S.C. 7703(b)(2))