Statistical considerations
for study on the effect of one variable on another

Significance Level -- 21sided (default= .05, 2 sided).

Enter two of the following three values and remaining value will be calculated.

1. Power, usually .8 or .9.
2. Total number of patients.
3. Minimal detectable difference(Change in the dependent variable per unit change in the independent variable, If the standard deviations, above, are not known the units are "standard deviations")