Points Earned vs. Hours studied

[email protected] wrote:Hi Sri,

The second question on this page asks for the MEDIAN of the number of hours studied. The word "median" is a statistical term that means "the middle number of the group", so we have to make sure the numbers are in order from least to greatest and then find the one in the middle. Here, we're told that there are 33 students, so the median will be the 17th number.

Each of the colored "dots" in the table represents a student, so we just have to count until we hit the 17th one (either from left to right or from right to left).

When counting from left to right, here's what I see:
5 students studied 1 hour
9 students studied 2 hours
8 students studied 3 hours

The 17th student will fall into the "3 hours" group.

GMAT assassins aren't born, they're made,
Rich

[email protected] wrote:Hi Sri,

My apologies for not answering both questions in the initial post.

For the second question, you can absolutely calculate the average of the three groups, but you can also "eyeball" the table to tell which group has the smallest average study time. It's important to note that each group consists of 11 students each.

Notice how most of the points are clustered around 2 hours and 3 hours.... Groups A (the white circles) and B (the blue squares) have many terms each that are greater than 3, which would push their averages "up"; Group C (the black circles) has only 1 term above 3 (just one 4) and 2 terms at the lowest level (1 hour), which means that this must be the group with the lowest average study time.

While certain chart/graph/table questions in the IR section will require a calculation, many will not. Keep an eye out for questions that require a specific numerical answer vs. those the require a non-numeric answer. The ones that don't require a numeric answer are ones that you can likely answer by spotting a pattern.

GMAT assassins aren't born, they're made,
Rich