SAMPLING

HI SIR , PLEASE CAN U HELP WITH VALUE WEIGHTED SAMPLING.. I UNDERSTAND ITS BASED ON MONETARY VALUE AND THIS IS AN ILLUSTRATION I FOUND.

Total value of receivables population is $500,000 and sample size is 5.
$500,000 / 5 = $100,000 so select every $100,000
Customer Balance Cumulative Total Selected Y/N
$ $
A 20,000 20,000 N
B 60,000 80,000 N
C 10,000 90,000 N
D 90,000 180,000 Y
E 50,000 230,000 Y
F 30,000 260,000 N
G 70,000 330,000 Y
H 80,000 410,000 Y
I 40,000 450,000 N
J 50,000 500,000 Y
Total 500,000

Every 100000 is selected which is the interval. so 180000 is above 1000000 so customer D is selected.
THen E as well.. But why was customer F not selected ? ITS ALSO ABOVE 100000 ?