Using Empirical Rule for Data???

[ddawg09]

I have 3 columns of data and I have to use the empirical rule for all 3 columns to find the upper limits and get rid of all oulier data points. Is there any easy way to do this?

[Leith Ross]

Hello ddawg09,

Is each column a separate sample or total population, or are the columns one sample or a population? Is the upper limit Z-score 1 (68%) or something else?

Sincerely,
Leith Ross

[ddawg09]

Hello ddawg09,

Is each column a separate sample or total population, or are the columns one sample or a population? Is the upper limit Z-score 1 (68%) or something else?

Sincerely,
Leith Ross

Yeah, each of my 3 columns is separate and so I have to use the Empirical Formula for all 3. I just wanted to see if there was an easier way then finding the average and standard dev. and then finding the % of points in each range.

[Leith Ross]

Hello ddawg09,

The Empirical Formula is dependent on a Normal (Gaussian) distribution. Excel has all the functions built in to solve for Standard Deviation, Average, and Normal Distrbution. Here is a list of Worksheet Formulas that should help make it easier.

STDEV Finds Standard Deviation of a Population Sample (unbiased)
STDEVP Finds the Standard Deviation of a Population
AVERAGE Returns the Arithmetic Mean of a number series
NORMDIST Returns the normal cumulative distribution for the specified mean and standard deviation.
NORMSDIST Takes a Z value. Z is the value for which you want the distribution.

Sincerely,
Leith Ross