Specifying the units for componentsmain topic how to
Specifying the units for componentsIf you did not change the total for the mixture from the default value of one, Minitab uses proportions to store your data. (This is equivalent to an amount total equal to one.) If you did change the total for the mixture, Minitab uses amounts - what you actually measure - to express your data. Depending on the mixture total and the presence of constraints, you may want to represent the design in another scale.
You can choose one of three scales to represent the design: amounts, proportions, or pseudocomponents. With certain combinations of the mixture total and lower bound constraints, the various scalings are equivalent as shown in the following table:
|
Total mixture |
Lower bound |
Equivalent scales |
|
equal to 1 |
0 |
amounts |
|
equal to 1 |
greater than 0 |
amounts |
|
not equal to 1 |
0 |
proportions |
|
not equal to 1 |
greater than 0 |
none |