To find the median of a set of numbers, we need to follow a specific process. The median represents the middle value when the numbers are arranged in order. Let's break down the steps to calculate the median for the given set: 154, 130, 144, 137, 156, 146, 138, 149, 160, 138.
First, arrange the numbers in ascending order (from smallest to largest):
130, 137, 138, 138, 144, 146, 149, 154, 156, 160
Count how many numbers are in the set. In this case, there are 10 numbers.
Let n be the total count of numbers. So, n = 10.
Since there is an even number of data points (n = 10), the median is the average of the two middle numbers. The positions of these middle numbers can be found using the formulas:
Applying this to our set:
Now, find the numbers at these positions in the sorted list:
To find the median, calculate the average of the two middle numbers identified in the previous step.
Median = $\frac{\text{Value at } n/2 \text{ position} + \text{Value at } (n/2) + 1 \text{ position}}{2}$
Median = $\frac{144 + 146}{2}$
Median = $\frac{290}{2}$
Median = 145
Therefore, the median of the given set of numbers is 145.

The above frequency chart shows the frequency distribution of marks obtained by a set of students in an exam. From the data presented above, which one of the following is CORRECT?