Sample size for a descriptive study of a continuous variable
Instructions: Enter parameters in the red cells. The answer will appear in blue below.
Standard normal deviate for α = Zα =
Sample size = N = 4Zα2S2/W2 =
Reference: Hulley SB, Cummings SR, Browner WS, Grady D, Newman TB. Designing clinical research : an epidemiologic approach. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013. Appendix 6D, page 80.