The graph above shows the distribution of the number of days spent on business trips in by a group of employees of Company W. Based on the graph, what is the median number of days spent on business trips in for these employees?
This is a typical reading comprehension question – the fact that it is in the math section indicates we need to be familiar with key concepts of graph reading and in this case with the definition of the median.
The median is a statistic (a number that represents a group that can be ordered and ranked) which has half the group members above it and half below it. In case we have an even number of group members it will be the average of the two members that are closest to the middle.
As we discussed in previous posts, we first want to be able to read the data in the graph. Choosing randomly the third bar from the left we make sure we read it as: “5 employees spent 22 days on business trips in 2010”.
Now, the median will be the number of days spent on business trips in 2010 that half the employees traveled less than and half traveled more than.
How many employees do we have presented in the graph?
That mean we are looking for the number of days the 16th worker traveled (15 employees or half traveled less or the same and 15 employees – or the other half traveled more).
Counting from the left 5+6+5=16.
The 16th employee traveled then 22 days.
34% out of 218,000 got it right.