how to solve

You are analyzing data about the number of hours university students work per day. The frequency distribution shows that most students work between 4 to 6 hours. If you want to calculate the cumulative relative frequency for students working up to 5 hours per day, which value should you expect for cumulative relative frequency if 85% of students work 5 hours or less? Choose only ONE best answer. A 0.85 B 0.55 C 0.30 D 1.00