(4) The student-to-media assistant ratio is 500:1;

(5) The student-to-health staff ratio is 800:1;

(6) The student-to-school administrative staff ratio is 315:1; and

(7) The student-to-clerical staff ratio is 200:1.

3.__Number of staff positions required.__The commissioner shall identify for each school administrative unit, using the pupil count arrived at under section 15674, subsection 1, paragraph C, subparagraph (1), the number of staff positions that are required in order to achieve the student-to-staff ratios set forth in subsection 2.

4.__Estimated salary costs.__The commissioner shall determine the estimated salary costs for the number of staff positions required under subsection 3.__In order to calculate this amount, the commissioner, where appropriate, shall use the salary matrix pursuant to section 15677 for all staff positions in each category.

5. Salary costs for substitute teachers.__The commissioner shall calculate the additional salary costs for substitute teachers for each school administrative unit using the pupil count arrived at under section 15674, subsection 1, paragraph C, subparagraph (1).__In order to calculate this amount, the commissioner shall establish a per-pupil rate for the cost of a substitute teacher for 1/2 day.

6. Total salary and benefit costs for staff.__The total salary and benefit costs for staff is equal to the sum of:

A.__The estimated salary costs determined pursuant to subsection 4;

B.__The amount, as determined by the commissioner, that equals the statewide percentage of estimated salary costs determined pursuant to subsection 4 that represents the statewide benefit costs; and

C. The substitute teacher salary costs determined pursuant to subsection 5.

§15680.__Per-pupil amounts not related to staffing