SAS problem: sum up rows and divide till it reach a specific value

Question

I have the following problem, I would like to sum up a column and divide the sum every line through the sum of the whole column till a specific value is reached. so in Pseudocode it would look like that:

data;
set auto;
sum_of_whole_column = sum(price);
subtotal[i] = 0;
i =1;
do until (subtotal[i] = 70000)
subtotal[i] = (subtotal[i] + subtotal[i+1])/sum_of_whole_column
i = i+1
end;
run;

I get the error that I haven't defined an array... so can I use something else instead of subtotal[i]?and how can I put a column in an array? I tried but it doesn't work (data = auto and price the column I want to put into an array)

data invent_array;
set auto;
array price_array {1} price;
run;

EDIT: maybe the dataset I used is helpful :)

DATA auto ;
  LENGTH make $ 20 ;
  INPUT make $ 1-17 price mpg rep78 ;
CARDS;
AMC Concord        4099 22 3 
AMC Pacer          4749 17 3 
Audi 5000          9690 17 5 
Audi Fox           6295 23 3 
BMW 320i           9735 25 4 
Buick Century      4816 20 3 
Buick Electra      7827 15 4 
Buick LeSabre      5788 18 3 
Cad. Eldorado     14500 14 2 
Olds Starfire      4195 24 1 
Olds Toronado     10371 16 3 
Plym. Volare       4060 18 2 
Pont. Catalina     5798 18 4 
Pont. Firebird     4934 18 1 
Pont. Grand Prix   5222 19 3 
Pont. Le Mans      4723 19 3 
;
RUN;