A researcher measures the diameter d d\,d of a synthetic polymer fiber at three different positions along its length.
They record the following three measurements:
1.26×10−4 m,1.19×10−4 m,1.22×10−4 m 1.26 \times 10^{-4}\text{ m}, \quad 1.19 \times 10^{-4}\text{ m}, \quad 1.22 \times 10^{-4}\text{ m} 1.26×10−4 m,1.19×10−4 m,1.22×10−4 mCalculate the mean diameter of the fiber in micrometres (μm\mu\text{m}μm) to an appropriate number of significant figures.