help with data points - (Jul/23/2013 )

If I have a set of 3 data points, 27, 26, 35 and another set of 3 data points: 26, 26, 27, what is the excel formula that tells me that in first set of data there is a discrepency (the 35 is an outlier).

You mean the delete key?

There are a number of tests available for identifying outliers (or, more correctly, identifying when the population is non-normal). The simple ones can be easily performed in Excel with the t.test function.
But ignoring outliers is a dangerous route to go down and can easily start to look like falsifying data. Better to repeat the experiment to gather more data and tighten the parameter estimation.