Final answer:
The median is a number that measures the center of the data. When a data set has an even number of data values, the median is equal to the average of the two middle values when the data are arranged in ascending order. When a data set has an odd number of data values, the median is equal to the middle value when the data are arranged in ascending order.
Step-by-step explanation:
The median is a number that measures the center of the data. You can think of the median as the middle value, but it does not actually have to be one of the observed values. It is a number that separates ordered data into halves. Half the values are the same number or smaller than the median, and half the values are the same number or larger.
When a data set has an even number of data values, the median is equal to the average of the two middle values when the data are arranged in ascending order. When a data set has an odd number of data values, the median is equal to the middle value when the data are arranged in ascending order.
So, the correct answer is A. The middle point in a data set.