Using awk of summation for specific range

I have a file of 5 columns:

1   1311    2   171115067   1.1688e-08
1   1313    3   171115067   1.75321e-08
1   1314    4   171115067   2.33761e-08
2   1679    5   135534747   3.68909e-08
2   1680    2   135534747   1.47564e-08
3   688 34  191154276   1.77867e-07
3   689 38  191154276   1.98792e-07
3   690 39  191154276   2.04024e-07

I need to sum the multiplication of ($2*$3) then divid it by distinct value of $4 for each range of $1

So, as an example:

within value 1 in $1, I should have: [1311*2+1313*3+1314*4]/171115067 for 2 in $1: [1679*5+1680*2]/135534747

And so on till the end (not necessary just to 3), so at the end sum the results of each value range

What I tried is: awk '{sum+=($2*$3)/$4} END { print "Result = ",sum}'

but that give me the sum of the multiplication for all together divided by each time which not what I need

Any help with that please?