Frequency count with multiplier value

[scheij]

I would like to tabulate the frequency of Column B values into Column C bins while also taking into account the factor in Column A.  Any suggestion to obtain the desired frequency in Column E without many manual insert row/copy/paste steps would be appreciated.  The file is uploaded too.  Thanks.

Number	Length	Bin	Frequency	Desired frequency
1	10	10.4	1	1
1	10.5	10.9	3	3
1	10.5	11.4	5	13
1	10.8	11.9	11	25
1	11		0		←extras
4	11		20	42	←sum
4	11
3	11
1	11.2
2	11.5
1	11.5
2	11.5
3	11.5
5	11.5
3	11.5
5	11.5
1	11.6
1	11.6
1	11.6
1	11.7
42					←sum

[#2]

@scheij 

See attached file.

[#3]

@scheij As a variant

=SUMPRODUCT($A$2:$A$21*($B$2:$B$21<=C2)*($B$2:$B$21>=N(C1)))

in E2 and copy it down to E5.

See attached 

[#4]

Thank you. The =SUMPRODUCT function will be very helpful for us in many applications.