... into the strata in Figure 9. 17 Stratification: £ Amount Number – 9, 999 .99 £ Total amount 1,400 2,800,000 10,000 – 19, 999 .99 150 2,000,000 20,000 – 29, 999 .99 65 1,500,000 30,000 – 39, 999 .99 35 ... £80, 000 and then extract a sample of 100 further payments using three value-based strata: Stratum £ Range 0 9, 999 .99 10,000– 29, 999 .99 30,000– 79, 999 .99 80,000 and over Total amount 2,800,000 3,500,000 ... This is based on the theory that the mean of a distribution of sample means is equal to the mean of the population from which the sample is drawn It is important to know the SD of the sample that...