The data analysis questions on the GRE Quantitative Analysis (i.e. Math) section require skills such as “describe past and present trends, predict future events with some certainty…” *(The Official Guide to the GRE)*. What that means for the test-taker is that questions will contain frequency distributions, bar graphs, circle graphs, histograms, scatterplots, and time plots.

This is an example of a histogram. The Y axis will often have probability or, in this case, frequency. The percentages you see in the picture are frequencies that simply refer to how often the event in the X axis occurred. In this case, we are told that out of a total of **25 **families, the children were chosen for something. There were six families who had 3 children and one can see on this histogram that the probability of one of those being chosen is 6/**25** or 24%.

(Look at the x value of 3 and follow with your finger to the top where it would match about 24% on the Y axis.) This is the kind of histogram interpretation that would be involved in an actual question.

Other data analysis questions may not involve a chart, but just be represented as a word problem. For example, when given daily temperatures for 5 days in July, one would have to find the mean, median, mode and range. A follow-up question might involve changing the given temperatures and then figuring the new quantities.

5 days in July: 90, 88, 85, 85, 87

Mean = (90+88+85+87)/5 = 87

Median = the number in the middle when put in order= 87

Mode = the most frequent number= 85

Range = the difference between the highest and lowest quantity= 5

If each day was 5 degrees cooler, what would the new mean, median, mode and range be? (82, 82, 80, 5)

Hopefully this quick summary has been helpful.

Best of luck! Tanya Panossian-Lesser