Average the closets two out of three number

[barryg1960]

I have the three numbers in a single row (column B, C, &D). I need a formula that will pick the two numbers out of those three and average them. 

Example:

The formula looks ate column B row 1, column C row 1, & column D row 1. It will determine that column B and Column C have the two numbers out of the three that are closets to each other and average them (Column B and Column C). It will do the same for row 2 and determine that column B and Column D are the closets

B	C	D	E
3109	3088	2500
2808	2765	2850

[#2]

@barryg1960 

In E1:

=IF(ABS(B1-C1)<=MIN(ABS(C1-D1),ABS(D1-B1)),AVERAGE(B1,C1),IF(ABS(C1-D1)<=MIN(ABS(D1-B1),ABS(B1-C1)),AVERAGE(C1,D1),AVERAGE(D1,B1)))

Fill down.