Magnification of the microscope = 100
Average width of the hair in the field of view of the microscope = 3.5 mm
\(\therefore\) Actual thickness of the hair is \(\frac{3.5}{100}\) = 0.035 mm.
Find the mean deviation about the mean for the data 38, 70, 48, 40, 42, 55, 63, 46, 54, 44.