How to use Excel DAVERAGE formula

							This is the Database range.
Product	Wattage	Life Hours	Brand	Unit Cost	Box Quantity	Boxes In Stock	Value Of Stock
Bulb	200	3000	Horizon	£4.50	4	3	£54.00
Neon	100	2000	Horizon	£2.00	15	2	£60.00
Spot	60						£0.00
Other	10	8000	Sunbeam	£0.80	25	6	£120.00
Bulb	80	1000	Horizon	£0.20	40	3	£24.00
Spot	100	unknown	Horizon	£1.25	10	4	£50.00
Spot	200	3000	Horizon	£2.50	15	0	£0.00
Other	25	unknown	Sunbeam	£0.50	10	3	£15.00
Bulb	200	3000	Sunbeam	£5.00	3	2	£30.00
Neon	100	2000	Sunbeam	£1.80	20	5	£180.00
Bulb	100	unknown	Sunbeam	£0.25	10	5	£12.50
Bulb	10	800	Horizon	£0.20	25	2	£10.00
Bulb	60	1000	Sunbeam	£0.15	25	0	£0.00
Bulb	80	1000	Sunbeam	£0.20	30	2	£12.00
Bulb	100	2000	Horizon	£0.80	10	5	£40.00
Bulb	40	1000	Horizon	£0.10	20	5	£10.00
To calculate the Average cost of a particular Brand of bulb.
			Brand	These two cells are the Criteria range.
		Type the brand name :	sunbeam
		The Average cost of sunbeam is :	£1.24	=DAVERAGE(B3:I19,F3,E23:E24)
What Does It Do ?
This function examines a list of information and produces and average.
Syntax
=DAVERAGE(DatabaseRange,FieldName,CriteriaRange)
The DatabaseRange is the entire list of information you need to examine, including the
field names at the top of the columns.
The FieldName is the name, or cell, of the values to be averaged, such as "Unit Cost" or F3.
The CriteriaRange is made up of two types of information.
The first set of information is the name, or names, of the Fields(s) to be used as the basis
for selecting the records, such as the category Brand or Wattage.
The second set of information is the actual record, or records, which are to be selected, such
as Horizon as a brand name, or 100 as the wattage.
Formatting
No special formatting is needed.
Examples
The average Unit Cost of a particular Product of a particular Brand.
			Product	Brand
			Bulb	Horizon
		The average of Horizon Bulb is :	£1.16	=DAVERAGE(B3:I19,F3,E49:F50)
This is the same calculation but using the actual name "Unit Cost" instead of the cell address.
			£1.16	=DAVERAGE(B3:I19,"Unit Cost",E49:F50)
The average Unit Cost of a Bulb equal to a particular Wattage.
			Product	Wattage
			Bulb	100
		Average of Bulb 100 is :	£0.53	=DAVERAGE(B3:I19,"Unit Cost",E60:F61)
The average Unit Cost of a Bulb less then a particular Wattage.
			Product	Wattage
			Bulb	<100
		Average of Bulb <100 is :	£0.17	=DAVERAGE(B3:I19,"Unit Cost",E67:F68)