The middle price refers to the middle price between the buying price and the selling price. Divide the sum of the buying price and selling price by 2. If the buying price and selling price of USD/JPY of ICBC are 1 18.90 and 1 19.20 respectively, the median price is 1 19.05.
( 1 18.90+ 1 19.20)/2 = 1 19.05