The median is the center by position after data are ordered, not the value in the middle row of a table. For an even number of observations, average the two middle values. A Desmos list can calculate the median of unsorted data, but enter repeated measurements separately so every observation counts.
Hints
- Hint 1
The median depends on ordered positions, not the order in which phones appear in the table. Enter all eight battery lives into one Desmos list. Does any battery life appear for two different phones?
- Hint 2
An even-sized data set has two middle positions. For eight values, they are positions and after sorting. Which battery lives occupy those spots when every phone is counted?
- Hint 3
The median of an even-sized list is the average of its two middle values. Once your list is saved as , type in Desmos. Check that you haven't skipped a repeated value.
Step-by-step
List the data and locate the middle
Step 1Enter every phone's battery life
Type into Desmos. It saves the eight battery lives as list . Keep both entries: phones F and G are separate observations.
- Step 2
Put the battery lives in order
The table is arranged by phone, not by battery life. Order the eight entries from least to greatest:
- Step 3
Find the two middle positions
The median is the middle of ordered data. With eight phones, positions and are in the middle. For an even count, average the two middle ordered values. The middle rows of the original table don't work because that table isn't ordered by battery life.
- Step 4
Read the median in Desmos
Type below the saved list. Desmos shows , the average of the two middle values. The median battery life is hours. Choice C.