Hello; I'm curious to know how he got 195 after adding the Deviation Squared column; Second, can you break down how he arrived at the 2.59? I haven't done square roots in too many years, and I don't know how to break it down.

NOTE: Standard Deviation is never negative. Calculating SD without technology is difficult. We will calculate a simple example by hand Ex: 2, 5, 6, 7,9 MEAN = 5.8 Data Value Deviation = Data Value - Mean 2 Deviation Squared 2 - 5, 8 ( 2 - 5,8) 2 5 5- 5, 8 ( 5 -5.8) 2 6 6- 5, 8 ( 6 - 5. 8) 2 7 7- 5,8 ( 7 - 5, 8 ) 2 9 9 - 5. 8 ( 9 - 5, 8 ) 2 ADD : 195 NUMBER: 5 STANDARD OF VALLIES DEVIATION 95 5 2.59