To estimate the accuracy and precision of the method within a day, prepare five spiked QC samples at three different concentrations: LLOQ $(8\mathrm{.}3$ ng$/$m$),$ QCL $(25$ ng$/$mL$),$ QCH $(4556$ ng$/$mL$).$

See the calculated concentrations in the table below $($QC$1$ QC$5).$ Calculate CV$\%$ as a measure of method precision and relative bias $(\%)$ as a measure of method accuracy. Based on the results, determine whether the method's precision and accuracy are acceptable. Also discuss the concepts of precision and accuracy and what they mean in practice.