The square root must be between 7 and 8 integers numbers.
By calculating the square roots of all numbers you have:
√47 = 6.85
√48 = 6.92
√58 = 7.61
√60 = 7.74
There are two square roots between 7 and 8.
By the position of point E at the number line, you can consider that the square root is √60 = 7.74.