Please help with a and b. I understand how to do it using the reciprocal method but I need help with the step sequencial method. Thank YOU!

Campaign Printing has two service departments, S1 and S2, and two production departments, P1 and P2. The data for May were as follows: Allocate service department costs (S1 & S2) to the production department (P1 & P2) using the step method with the sequence of allocation based on the highest percentage support concept. Compute the total amount of support costs allocated to each of the two production departments P1 & P2