## Line Graphs

As we’ve seen, line graphs are one major type of graph found on the CAT. These graphs depict independent points on an x-y grid that are then connected with a line, or several lines, to show trends. When it comes to line graphs on the CAT, you can expect to encounter the following type of questions (among others).

- At which (x-unit, such as year) was (y-unit, such as profit) the highest/lowest?
- The difference between (two given points) is closest to… [answer choices may be given in real numbers, percentages, or other units].
- Which of the following is closest to describing the percent change in (the subject of the graph) from (x-unit to x-unit)?

## Bar Graphs

Bar graphs are another important type of graph you’ll encounter on the CAT. The testmakers may make these problems more complicated by depicting clusters of bars. For example, one cluster may provide different types of data (e.g. men, women, children) for a given year. On the other hand, they may use different colors on a single bar to provide more than one piece of data for a given x-unit.

Bar graphs are another way of depicting information that could be shown on a line graph. Thus, you can expect to encounter similar question types.

- By what percent did (y-unit) increase from (x-unit) to (x-unit)?
- What was the total number of (y-unit) for (series of x-units)?
- If (a given percentage) of (y-units) were (in a specialized group, divided by gender, class, etc.), how many were there in (x-unit)?

## Tables

Tables on the CAT can be deceptively simple. The stimuli themselves may appear to be straightforward in terms of the information they provide. On the other hand, the questions can be tricky. More complex questions may challenge you to estimate ratios or percentages, calculate rates of change or profit growth, or consider a variety of data from several different tables. Other types of questions you may encounter include the following.

- Which of the following statements [about the data in the table] is (correct/incorrect)?
- Factor A as a percentage of total (units the table is measuring) is the (least/greatest) in which sector?
- In which category is (item measured by the table) the (second/third/fourth/etc.) (least/greatest) in terms of the total output?

## Pie Charts

Pie charts divide a whole into different portions, indicating the percentage of the whole that each portion comprises. For example, you might come across a pie chart of a country’s exports. Each export could be indicated by a slice of the pie, proportional to the relative size of that export. You’ll find the questions about pie charts similar to those about graphs. The major difference is that you’ll most likely begin with the percentages and have to convert to real numbers or ratios (rather than vice-versa).

Because we’re not used to seeing pie charts in everyday life, they can be intimidating when you’re first tested them. This is especially true because the CAT likes to provide these in mixed stimuli sets. We’ll see more on these below. However, familiarity with this graphic type will make the questions far more manageable.

## Word Problems

You may remember word problems from school, and wonder why you can find these in DI as well as in Quantitative Ability on the CAT. DI word problems will have more to do with dividing a whole (such as a student body, employees at a company, etc.) into smaller parts (according to gender, time at the institution, etc.). Then, you’ll answer questions similar to those you’d find elsewhere in DI about relative proportions, the effects of a decrease or increase in one particular sector, the minimum number of x needed to produce y, and so forth.

## Mixed Stimuli

You’ll most likely encounter mixed stimuli—i.e. two or more of the above graphic types in combination—on at least one CAT DI problem set. Usually, these problems involve “translating” information from one of the graphics to the other. These translations might involve calculating a percentage or ratio of a given number or set of numbers, figuring out total units from a percentage or ratio, and similar types of functions.

## Using Question Types to Create a Syllabus

With these six problem types in mind, evaluate your performance on mock CAT DI sections. (If you haven’t taken a mock CAT, you definitely should before the official test!) Which kind of graphic stimuli challenge you the most? Which do you find easier to interpret? Evaluate your answers to a DI section—or, preferably, a series of DI sections, and build a study syllabus from there. Focus primarily on your weaker areas, but don’t forget to keep reinforcing your strengths by mixing in problems from those areas throughout your practice. That way, on the official exam, you won’t have forgotten anything that will keep you from getting the score that you want!

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