Final answer:
To find the median number of students in each group attending a school dance, collect and order the data on the number of students, then identify the central value if the data set is odd, or the average of the two central numbers if the data set is even.
Step-by-step explanation:
To find the median number of students in each group attending a school dance, we follow a specific set of steps:
- Firstly, collect the data on the number of students in each group.
- Secondly, order the data from least to greatest.
- If the number of data points is odd, the median is the middle number. If the number of data points is even, the median is the average of the two middle numbers.
- Finally, identify the median value.
For example, if the recorded numbers of students in each group are 5, 10, 15, 20, and 25, then the median number of students would be 15, as it is the middle value of the ordered set.
Using the provided Example 2.23, where 15 student exercise times are recorded, we would first order the times: 0, 0, 10, 20, 30, 30, 30, 40, 45, 60, 60, 60, 90, 120, 300. With 15 data points (an odd number) the median is the middle value, which in this case is 40 minutes.