It would help if you could post the full query in the thread with the DDL for the indexes on the tables in the query.

A key lookup is used when all the columns the query needs are not contained in the index, the database engine will have to go to the clustered index (actual...

You can write a Table Valued Function (tvf) as in the article you posted, I believe this may be more efficient than a scalar-valued function:

IF OBJECT_ID(N'dbo.tvfNORMALDIST', N'IF')...

if you still want me to provide some data and/or results I get in Excell or the SQL I use to get the data then just let me know...

It is not just rounding in a single computation. When you have a set of floats, you also get skew in the set as a whole, either away from...

Yes it is, the article is incorrect when it states "The variance (s) is the square root of the standard...

I know that floating-point numbers are approximate. The errors you are referring to would only apply to the least significant digits of the result. But all the OP wants to...

This is not the purpose of SQL. We are a database language; you really ought to be using a statistical package. You can write out the formula for the...

If you know the mean (µ) and variance (sigma²) you can plot a normal p.d.f.

In t-sql the mean is AVG(), the variance is VAR()

It would be helpful...

Sorry, I didn't read which forum...

If you know the maximum number of rows for any Id in the table you could construct a query like this:

 SELECT Id, 
   ...

Something like this?

;WITH CTE AS 
(
    SELECT DISTINCT T.ID 
      FROM @T T
)
SELECT * 
  FROM CTE
 CROSS...

Can you give the expected output?

Like so:

SELECT EmpName,
    MAX(CASE WHEN row_num = 1 THEN Item END) AS item1,
    MAX(CASE WHEN row_num = 2 THEN Item...

As Alejandro Santana says, just make sure the recovery model is set to Simple.