Calculating the Exact Characteristics of Truncated Sequential Probability Ratio Tests Using Mathematica

As a result of pressures to cut pesticide use, schemes are in use or are being developed which involve sampling a crop for pests and only treating the crop if the pest is found in sufficient quantities to justify the use of the pesticide. Such schemes are known as supervised pest control. Although they produce a saving of pesticide, the cost of sampling is high and it is important that the sampling should be done as efficiently as possible.