Use the data for the following question:

Table VII
Urea Nitrogen Concentration in 9 Employees (mg/dL)

Concentration (mg/dL)	x-	(x-)2
10
11
11
13
9
5
15
7
9
Total

What is the standard deviation of the above data? You may find it helpful to make a chart similar to the one above.

Please select the single best answer

	2 mg/dL
	2.5 mg/dL
	2.7 mg/dL
	3 mg/dL