title: Calculating standard deviation using stats
body: <p>I have the following data set,</p>
  
  <pre><code>1.54    23.66
  1.75    26.25
  1.92    30.20
  2.08    34.46
  2.44    42.08
  2.78    46.81
  3.03    51.10
  3.70    52.99
  4.17    56.15
  4.76    59.34
  </code></pre>
  
  <p>To calculate the Standard Deviation 
  (SD) of the first two points, I use,</p>
  
  <pre><code>stats "data.dat" u 2 every ::0::1
  </code></pre>
  
  <p>However, this is giving me the wrong 
  SD = 1.2950 (The correct being 1.83) </p>
  
  <pre><code>* FILE: 
    Records:      2
    Out of range: 0
    Invalid:      0
    Blank:        0
    Data Blocks:  1
  
  * COLUMN: 
    Mean:         24.9550
    Std Dev:       1.2950
    Sum:          49.9100
    Sum Sq.:    1248.8581
  
    Minimum:      23.6600 [0]
    Maximum:      26.2500 [1]
    Quartile:     23.6600 
    Median:       24.9550 
    Quartile:     26.2500 0
  </code></pre>
  
  <p>So what am I doing wrong? TIA.</p>