Question

What is dollar unit sampling, please explain?

Answer 1

Suppose we have a items of amounts x₁ , x₂ , ...,x_n . Also suppose that the amounts of the items are not same .

Then we want to select the items using dollar unit sampling for testing them. So we want to specify the interval , say $1000 Then find the cumulative sum up to specified value $1000. And select the item where we hits $1000. Then again repeat the same process from the just next unit.

Let x₁ = 415 , x₂ = 275, x₃ = 450 , x₄ = 720 x₅ = 300 , x₆ = 556

Then we have the following column for the selection of the items.

The hits occurs corresponding to the x₃ and x₅ so the are selected for study.

Note that : The basic idea is that each dollar is a sampling unit, and as such, this method is more likely to select higher dollar items for testing.