power alpha sample size

  1. J

    Calculate sample size?

    You are interested in studying the relationship between sodium consumption and the development of hypertension. 32% of Americans are hypertensive (systolic blood pressure>140), and a further 29% are prehypertensive (140≥SBP>120). Detecting a 1 mm Hg SBP elevation with 80% power at the 0.05%...
  2. L

    Power and sample size calculation for neuroscience

    Dear TalkStats, I have searched the forum but cannot find the answer I am looking for, if you could help that would be great! I am recording cells and their action potential frequency in two conditions (group 1 and group 2). (So it is a repeated measures.) How do I calculate the required...
  3. V

    Power and Alpha combinations for same sample size

    Let's say I have a sample size established with alpha=0.05 and power=0.8 (based on time constraint for study). So, the same sample size can be achieved with any of: alpha = 0.001 and power = 0.31 alpha = 0.01 and power = 0.58 alpha = 0.25 and power = 0.95 alpha = 0.999 and...