In a typical extra-tropical cyclone, the vertical motion of air is typically only 1% to 10% of the horizontal wind speed. If the horizontal wind in a cyclone is blowing at a rate of 20 km/h

In a typical extra-tropical cyclone, the vertical motion of air is typically only 1% to 10% of the horizontal wind speed. If the horizontal wind in a cyclone is blowing at a rate of 20 km/h, what is the positive difference between the greatest and least typical values for the vertical air motion? Express your answer as a decimal to the nearest tenth.