If 4/7 lies between the other numbers then 4/7>-3/5 but 4/7<3/4.
Since 4/7 is positive and -3/5 is negative, 4/7 is greater than -3/5 because all positive numbers are greater than negative numbers.
If 4/7 is less than 3/4, then 3/4-4/7 must be positive. 3/4-4/7=21/28-16/28=5/28, which is positive, so 4/7 lies between the two numbers.