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 \(\sqrt[2]{}\).

Step 2

Thus, the standard deviation of the estimate is, \(SD=\frac{7\times 10^{-15}}{\sqrt{2}}=4.9497\times10^{-15}\).

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 \(\sqrt[2]{}\).

Step 2

Thus, the standard deviation of the estimate is, \(SD=\frac{7\times 10^{-15}}{\sqrt{2}}=4.9497\times10^{-15}\).