# Hayes Accountants

## 02 Apr Hayes Accountants

Probability Chart of Results of Test Mailings

When you undertake a marketing activity that produces a result it would be great to know that if you repeated it, the same result would occur or if you did twice the amount, you would get twice the return and so on. Of course, there is no certainty. Nevertheless, the larger the sample size of the first test, the more confidently you can predict the results of additional marketing activities based on the probability of the result. The following table on the next page shows how to be 95% sure that additional mailings will produce a result within certain boundaries.

 If the size of the test mailing is And the return on the test mailing is Then 95 chances out of 100, the return on the identical mailing on the whole list will be between If the size of the test mailing is And the return on the test mailing is Then 95 chances out of 100, the return on the identical mailing on the whole list will be between 100 1% 0 & 2.99% 250 1% 0 & 2.26% 100 2% 0 & 4.80% 250 2% 0.23% & 3.77% 100 3% 0 & 6.41% 250 3% 0.84% & 5.16% 100 4% 0.08% & 7.92% 250 4% 1.52% & 6.48% 100 5% 0.64% & 9.36% 250 5% 2.24% & 7.76% 100 10% 4.00% & 16.00% 250 10% 6.20% & 13.80% 100 20% 12.00% & 28.00% 250 20% 14.94% & 25.00% 500 1% 0.11% & 1.89% 1,000 1% 0.37% & 1.63% 500 2% 0.75% & 3.25% 1,000 2% 1.12% & 2.88% 500 3% 1.48% & 4.52% 1,000 3% 1.92% & 4.08% 500 4% 2.25% & 5.75% 1,000 4% 2.76% & 5.24% 500 5% 3.05% & 6.95% 1,000 5% 3.62% & 6.38% 500 10% 7.32% & 12.68% 1,000 10% 8.10% & 11.90% 500 20% 16.42% & 23.58% 1,000 20% 17.48% & 22.52% 2,000 1% 0.55% & 1.45% 5,000 1% 0.72% & 1.28% 2,000 2% 1.37% & 2.63% 5,000 2% 1.60% & 2.40% 2,000 3% 2.24% & 3.76% 5,000 3% 2.52% & 3.48% 2,000 4% 3.12% & 4.88% 5,000 4% 3.45% & 4.55% 2,000 5% 4.03% & 5.97% 5,000 5% 4.38% & 5.62% 2,000 10% 8.66% & 11.34% 5,000 10% 9.15% & 10.85% 2,000 20% 18.21% & 21.70% 5,000 20% 18.87% & 21.13% 10,000 1% 0.80% & 1.20% 100,000 1% 0.94 & 1.06% 10,000 2% 1.72% & 2.28% 100,000 2% 1.91% & 2.09% 10,000 3% 2.66% & 3.34% 100,000 3% 2.89% & 3.11% 10,000 4% 3.12% & 4.39% 100,000 4% 3.88% & 4.12% 10,000 5% 4.56% & 5.44% 100,000 5% 4.86% & 5.14% 10,000 10% 9.40% & 10.60% 100,000 10% 9.81% & 10.19% 10,000 20% 19.20% & 20.80% 100,000 20% 19.75% & 20.25%