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 other type of instrument that gives music is the keyboard instrument. The keyboards are available in different types and one is the percussive like the piano. There is another type that can be plucked and played. The strings are plucked or striked to give you the sound.iolin (Image source: sxc.hu). The string instruments are used to produce sound with the help of vibration. The strings are to be pulled or plucked. The mode of use to create the vibration makes the difference in different string instruments.