Headshot Damage Reduction, question about one of the examples.

"targeting the head with the Sharpshooter perk against a player with 20% Headshot reduction results in": 1.5 + .1 - .2 = 1.4x headshot multiplier Is the +.1 from Sharpshooter? jw because the perk is +15% headshot location bonus, (+.15)?