0

Please login or register to vote for this query.

(click on this box to dismiss)

Q&A for ebook publishers and readers

CREATE TABLE #Numbers 
( 
  Number DECIMAL(10,4),
  Variance DECIMAL(10,4)
);
GO
INSERT INTO #Numbers (Number) VALUES
    (23),
    (37),
    (45),
    (49),
    (56),
    (63),
    (63),
    (70),
    (72),
    (82);
GO

DECLARE @Mean DECIMAL(10,4);
SET @Mean = (SELECT SUM (Number) / COUNT(Number) FROM #Numbers);
-- @Mean is 100
UPDATE #Numbers 
SET Variance = POWER( (@Mean - Number), 2);
DECLARE @StdVariance DECIMAL(10,4);
SET @StdVariance = (SELECT SQRT( SUM((1.0 * Number - @Mean) * (1.0 * Number - @Mean)) / COUNT(Number) ) FROM #Numbers);
SELECT 
  @Mean AS [Mean],
  @StdVariance AS [Standard Variance],
  Avg(Number) as [Avg],
  StDev(Number) as [StdDev]
from #Numbers

view current version

edited nov 3 14

created jan 17 14 rolfl