[tex]The \ standard \ deviation  = 
 \sqrt{ \frac{1}{n} \sum ( x_{i} -  \mu  )^2 } 
\\ where: \\
n \ is\  the \  number \  of  \ elements \\
 x_{i}  \ element  \ number \  i \\
\mu \ is \ the \ mean \ of \ the \ elements 
[/tex]
The elements are : 
                                2,3,5,8,2.03,2.20,2.6,4.5
n = 8
μ = ( 2 + 3 + 5 + 8 + 2.03 + 2.20 + 2.6 + 4.5
)/8 = 3.66625
sum = ( 2 - 3.66625)² + ( 3 - 3.66625)² + ( 5 - 3.66625)² + ( 8 - 3.66625)² + 
( 2.03 - 3.66625)² + ( 2.20 - 3.66625)² + ( 2.6 - 3.66625)² + ( 4.5 - 3.66625)²
      = 30.44 
∴ The standard deviation = √ (30.44 / 8)
                                         ≈ 1.95 ( to the nearest hundredth )