So suppose I'm given that my compound is eleven point 11% hydrogen and 88.89% oxygen. I have to follow three steps to find the empirical formula. In my first step, I make the assumption that I have 100 grams of my compound. And what I do is I convert this guy to fraction and this guy to fraction by dividing each guy by 100. And then I multiply each guy by my 100 grams of compound to find how many grams of each is in my compound. So, 100 grams of my compound multiplied by 0.111 which I got this guy divided by 100 equals eleven point 11 grams of h in my 100 grams of compound.