Mixture-Amounts Designs
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In the simplest mixture experiment, the response is assumed to only depend on the proportions of the components in the mixture. In the mixture-amounts experiment, the response is assumed to depend on the proportions of the components and the amount of the mixture. For example, the amount applied and the proportions of the ingredients of a plant food may affect the growth of a house plant. When a mixture experiment is performed at two or more levels of the total mixture amount, it is called a mixture-amounts experiment.