This set goes deeper on table questions from production and costs. It assumes you already know the basics of total, average and marginal quantities and want to work with awkward tables.
The four lessons below build on each other, and the practice set mixes them.
What does this set cover?
- Separating total, average and marginal quantities in a cost table.
- Recovering a missing cost value while the table stays consistent.
- Explaining why output growth need not imply higher productivity.
- Writing an economic explanation rather than repeating a calculation.
One short example: the table with a gap
A fictional stall’s total cost is RM100 at zero output, RM130 for 1 unit and RM154 for 2 units. The entry for 3 units is missing, but the marginal cost of the third unit is given as RM18.
Marginal cost is the change in total cost, so the missing entry is 154 + 18 = RM172. You never need to guess; the other columns fix the value.
| Units | Total cost (RM) | Marginal cost (RM) |
|---|---|---|
| 0 | 100 | none |
| 1 | 130 | 30 |
| 2 | 154 | 24 |
| 3 | missing | 18 |
The skill is to see which given figure links to the missing one. Here it is the marginal cost.
How do the parts connect?
Separating the three kinds of figure tells you which column can reveal the gap. Recovering the value then uses the relationship between the columns. Productivity then shows whether more output came from better use of inputs or from simply adding more of them, and the written explanation turns the numbers into economic reasoning.
Who should start where?
- Mix up average and marginal: start with the first lesson.
- Stuck when a cell is blank: start with recovering a missing value.
- Write “output rose so productivity rose”: start with the third lesson.
- Numbers right but answers short: start with the fourth lesson.
Test yourself with the integrated practice for this set. For a teacher to check your tables live, see online one-to-one Economics tuition.