When two variables are inversely proportional the relation between them can be written as:

Here, k is the constant of proportionality and is always equal to the product of the two variables. So using the given values of z and x, we can find k first.

The constant of proportionality for the given inverse proportion comes out to be 2. Using the value of k in the equation, we get:

We have to find the value of z when x=28. So replacing x by 28, we get:

Thus, rounding of to nearest thousand the value of z comes out to be 0.071 if x is equal to 28.