Basic calculations
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Suppose you have the following observations:

  5, 6, 5, 10, 1, 4, 9, 2, 3.

Without using any tool, calculate the following measures:

 - mean
 - median
 - mode(s)
 - sample size
 - minimum
 - maximum
 - first quartile
 - third quartile
 - interquartile range
 - range
 - mean
 - variance with n
 - variance with n-1
 - standard deviation with n-1
 - standard error