Standard deviation is the square root of variance, but variance is given by mean, so divide by number of samples. That is : 38.5/10 = 3.58. But standard deviation equals the square root of variance, so SD = the square root of 3.85 which is 1.96.
The virginal(s): The virginal, also called virginals, usually has a rectangular case with the keyboard across the wide side. As with the spinet, the strings run side-to-side relative to the player. Again, it saves on wallspace, and again they rate their own FAQ. Virginals were fairly early, 15th and16th centuries.
The staff is the fundamental latticework of music notation, on which symbols are placed. The five staff lines and four intervening spaces correspond to pitches of the diatonic scale â which pitch is meant by a given line or space is defined by the clef. In British usage, the word stave is often used.