Estimates variance based on a sample. In addition to numbers, text and logical values such as TRUE and FALSE are included in the calculation.
Syntax
VARA(value1,value2,...)
Value1,value2,... are 1 to 30 value arguments corresponding to a sample of a population.
Remarks

VARA assumes that its arguments are a sample of the population. If your data represents the entire population, you must compute the variance using VARPA.

Arguments that contain TRUE evaluate as 1; arguments that contain text or FALSE evaluate as 0 (zero). If the calculation must not include text or logical values, use the VAR function instead.

VARA uses the following formula:
Example
Suppose 10 tools stamped from the same machine during a production run are collected as a random sample and measured for breaking strength.
St1 
St2 
St3 
St4 
St5 
St6 
St7 
St8 
St9 
St10 
Formula 
Description (Result) 
1345 
1301 
1368 
1322 
1310 
1370 
1318 
1350 
1303 
1299 
=VARA([St1], [St2], [St3], [St4], [St5], [St6], [St7], [St8], [St9], [St10]) 
Estimates the variance for the breaking strength (754.2666667) 