Using the data below, how do you find power?
N= 465,714 Mean=23.95, 21.81
Std. Deviation= 4.734, 4.805
Std. Error Mean= .220, .180

First, find s2pooled . Then find g (the sample estimate of d) (remember to take the square root of s2pooled). Always use the absolute value of g (or d) for these calculations. Find δ and remember to replace d with g. Find the harmonic mean of the n’s because you have unequal sample sizes. Assuming α = .05 (two tailed), use the table to find the power.

Question

Using the data below, how do you find power?
N= 465,714 Mean=23.95, 21.81 
Std. Deviation= 4.734, 4.805 
Std. Error Mean= .220, .180

First, find s2pooled . Then find g (the sample estimate of d) (remember to take the square root of s2pooled).  Always use the absolute value of g (or d) for these calculations.  Find δ and remember to replace d with g.  Find the harmonic mean of the n’s because you have unequal sample sizes. Assuming α = .05 (two tailed), use the table to find the power.