Question # Two independent measurements are made of the lifetime of a charmed strange meson. Each measurement has a standard deviation of 7times 10^{−15} seconds. The lifetime of the meson is estimated by averaging the two measurements. What is the standard deviation of this estimate ?

Measurement
ANSWERED Two independent measurements are made of the lifetime of a charmed strange meson. Each measurement has a standard deviation of $$7\times 10^{−15}$$ seconds. The lifetime of the meson is estimated by averaging the two measurements.
What is the standard deviation of this estimate ? 2021-02-13
Step 1
It is given that the population standard deviation is $$7\times 10^{−15}$$.
The lifetime of the meson is estimated by averaging the two measurements.
The standard deviation of the two measurements is obtained by dividing the population standard deviation by square $$\sqrt{}$$.
Step 2
Thus, the standard deviation of the estimate is, $$SD=\frac{7\times 10^{-15}}{\sqrt{2}}=4.9497\times10^{-15}$$.