What is sorting for in Table Analysis?
GMAC presents this format as analyzing a sortable table to identify relevant data or data that meet certain conditions. Sorting reveals a ranking; it does not replace reading the prompt. Sorting by revenue does not automatically answer a question about the return rate.
We suggest breaking the question into three parts: population, operation, and decision. For example, “which stores in the East have more than 100 orders?” specifies a region, then a threshold. The second condition applies to the selected group, not indiscriminately to every row.
What do these order figures show?
Fictional data for one month. A returned order is included in the store’s order count. Amounts are in thousands of dollars; the return rate is calculated from the two order-count columns.
| Store | Region | Orders | Returned orders | Revenue ($000) |
|---|---|---|---|---|
| Alder | East | 120 | 6 | 18 |
| Birch | West | 80 | 8 | 16 |
| Cedar | East | 200 | 8 | 22 |
| Dune | West | 100 | 3 | 15 |
| Elm | East | 60 | 6 | 12 |
Which statements can the table confirm?
First, try to answer without copying the table. For a universal claim, one counterexample is enough to answer no. For an overall rate, write out the numerator and denominator before dividing.
For each statement, select Yes if it is supported by the table and No otherwise: (1) Every East store has a return rate below 6 percent. (2) Among stores with revenue above $15,000, Cedar has the lowest return rate. (3) The combined return rate for West stores is below 7 percent.
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The solution, step by step
(1) No. (2) Yes. (3) Yes.
The method in action
- Elm’s rate is 6/60 = 10%. This one store in the East disproves statement (1). Alder is at 5% and Cedar at 4%, but their lower rates do not make the universal claim true.
- Above $15,000 in revenue: Alder, Birch, and Cedar. Their rates are 5%, 10%, and 4%. Cedar has the lowest. Dune is not in the group: $15,000 is not strictly greater than $15,000.
- For the West: (8 + 3)/(80 + 100) = 11/180, or about 6.11%, which is below 7%. Add returned orders and total orders, not the percentages.
- The simple average of 10% and 3%, or 6.5%, is not the West’s rate. It would happen to lead to the same final decision here, but the method is incorrect.
The pitfall
The greatest number of returns does not imply the highest rate
Birch and Cedar each have eight returns, but their order volumes are 80 and 200. Their rates differ substantially. Comparing only the numerators gives a tie when the question asks for a proportion.
Conversely, revenue is not the denominator for an order return rate. It can help select a group without entering into the rate calculation. A column useful in one step is not necessarily the basis for every later operation.
How can you check a result without repeating every calculation?
When the volumes are positive, the combined rate for two groups must fall between their rates. The West’s rate should therefore be between 3% and 10%. Since Dune accounts for more orders than Birch, the combined rate should be closer to 3% than to 10%. This check does not replace the exact calculation, but it can reveal an inconsistent total.
Finish by rereading threshold words such as above, below, at least, and no more than. Note which operation actually helped. If sorting does not make a small table easier to read, you do not have to use it. For a larger table, choose the column that reduces the search effort.
Key takeaways
- Define the group before calculating.
- An overall rate uses totals, not a simple average of rates.
- Check strict inequalities and units.