A return series with 250 observations has a sample mean of 10 percent and a standard deviation of 15 percent. The standard error of the sample mean is closest to: A. 0.06. B. 15.80. C. 3.87. D. 0.95.
The standard error of the sample mean is the standard deviation of the sample divided by the square root of the number of observations in the sample. In this case, (15 / √250) = 0.95.
