(a)
The Superintendent of Public Instruction shall determine the average achievement testing scores in terms of state percentiles in elementary school districts for grades 1, 3, and 6 or 8, whichever is the last grade in the particular elementary school within the school district, in high school districts for grade 12, and in unified school districts for grades 1, 3, 6 or 8, whichever is the last grade in the particular elementary school within the school district, and 12, as measured by the 1966–1967 statewide administered achievement tests.
(b)
He shall compute the reciprocal value for each district achievement test score determined in subdivision (a).
(c)
He shall determine the lowest reciprocal value for achievement test scores under subdivision (b). Such lowest reciprocal value shall be assigned the weighting value of 1.00.
(d)
A weighting value for achievement test scores for each other district shall be computed by dividing the reciprocal value for each district determined under subdivision (b) by the lowest reciprocal value for achievement test scores determined under subdivision (c).