GMAT STATISTICS

[abhi75]

This is a graph problem. Can someone please explain it. Thanks for your help.

Abhi

[Stuart@KaplanGMAT]

We're asked for the median # of hours. We know that there are 35 people total, so the median person is the 18th (from either direction).

Starting on the left, we have:

9 people at 1 hour
4 people (total 13) at 2 hours
1 person (total 14) at 3 hours
2 people (total 16)at 4 hours
1 person (total 17) at 5 hours

So, the next person is the 18th, which makes the median # of hours = 6.

We could have counted from the right as well:

10 people at 7 hours
8 people (total 18) at 6 hours.

We hit the 18th person in the 6 hours column, so the median is 6.

[abhi75]

Thanks Stuart for showing how to approach this kind of problems.

Thanks.
Abhi

[ritetosha]

i have one doubt about your approach.

how does a median person give median no. of hours.?

[Stuart@KaplanGMAT]

i have one doubt about your approach.

how does a median person give median no. of hours.?

Hi,

when looking at statistical data, it is, not surprisingly, all about the numbers.

Consequently, regardless of whether you're talking about people or animals or money, you still just view each data point as a number in a set.

Accordingly, there's really no such thing as the "median person"; you just arrange the data in ascending (or descending) order and pick the middle number in the set.

So, even though I said "the 18th person", technically I should have said "the 18th data point"; practically, however, each means the same thing.