Explanation:
that depends on the result dimension of P(x).
if P(x) delivers the percentage in the form xx.xx%, then
H(x) = I(x) × P(x) / 100
if P(x) delivers the percentage in the form 0.xxxx, then
H(x) = I(x) × P(x)
very basically, the absolute amount of a percentage of a whole is the product between both (and divided by 100).
e.g.
let's say, the whole amount is $64,000.
and we need to know 10% of that.
10% of 64,000 is then
64,000 × 10 / 100 = 6,400
or
64,000 × 0.10 = 6,400
can you see the connection, and why both versions do the same ?