What is the true, molecular formula of a compound with the empirical formula C13H19O2 and molar mass of 414.64g?

C13H19O2 = (12 * 13) + (1 * 19) + (16 * 2) = 156 + 19 + 32 = 207.

The formula is n = molar mass of molecular formular / molar mass of empirical formular. MM of molecular formula = 414.7 and of empirical formula = 207

So n = 414.7 / 207 = 2.

So the true molecular formula is 2 (C13H19O9) = C26H38O18.