help formula

[xarrisx]

hello
I need some help with excel

I have this excel sheet

A B
1 11 2
2 0 3
3 5 1
4 2 4
5 ?

I want B5 to be the sum of the multiplication of the colums A and B.
I mean B5=(A1*B1)+(A2*B2)+(A3*B3)+(A4*B4)
I want a ranged version of this formula because i have too many rows and a
formula like the one above will take me a month to write it.

Thanks in advance!

 

[Frank Kabel]

Hi
=SUMPRODUCT(A1:A10,B1:B10)

 

[xarrisx]

Thanks it works!!!

Hi
=SUMPRODUCT(A1:A10,B1:B10)