You are correct! You arbitrarily assumed that you had 100 grams of this compound and multiplied 17.34 g of hydrogen atoms by 1 mol/1.01g to obtain 17.17 moles of hydrogen atoms. You calculated the moles of carbon atoms to be 6.88 moles by the same method and then divided both of these numbers by the smaller number (6.88) to get the smallest ratio...C₁H_2.5. You then multiplied this by 2 to obtain the correct answer.