Assuming the distribution of concentrations in the log scale to the base 2 is normal, obtain the best estimate of the variance of the concentrations from these data?

Obstetrics, Serology

A new assay is developed to obtain the concentration of M. hominis mycoplasma in the serum of pregnant women. The developers of this assay want to make a statement on the variability of their laboratory technique. For this purpose, 10 subsamples of 1 mL each are drawn from a large serum sample for one woman, and the assay is performed on each subsample. The concentrations are as follows: 2⁴, 2³, 2⁵, 2⁴, 2⁵ 2⁴ 23, 2⁴, 2⁴, 2⁵.