In a full - scale mixing trial, two liquids are mixed in proportions of 1:4. Samples removed
over a period and analyzed for the minor component, generated the following data:
Time (min) Variance
1 0.084
2 0.044
4 0.012
6 3.2 x 10⁻³
10 2.41 x 10⁻⁴

Determine the mixing time to ensure that 99% of all samples withdrawn from the mixer will contain + -7% of the mean concentration of the minor component.