What is the field of size at each magification for the micro

What is the field of size at each magification for the microscope listed below:
10x
25x
40x
100x
(Diameter of field of vew at 10x is 1.2mm)

Solution

Magnification

Field of size

10x 1.2

12

25x 1.2

30

40x 1.2

48

100x 1.2

120

With the field of diameter of the low powerfield as: 1.2mm