Dear Inspiration100;
I don’t believe hat you can apply the recipe of Question 4 of your link “directly” to the Clock Reaction.
Question 4 is only a hint how you may find out relations between concentrations changes and the influence of the Initial Rate (IR), but not its inital value self.
As you may see there: Doubling [B.] ends in Doubling IR; and triple the [A.] is (triple)2 the IR.
But that’s only valid for the particularly given Reaction and Data in Question 4, and nowhere else!
Sorry!, ─ At least I believe you will have to do it graphically, expect you like a lot of statistics instead.
Good Luck!
ARGOS++