The median is the middle value after the prices are ordered, not the value in the middle row of a table. For an unordered list, enter every price into a Desmos list named , then type . Keep duplicate prices: each station is a separate observation, and omitting one can change the middle value.
Hints
- Hint 1
The median is the middle price after sorting from least to greatest. With five prices, one position has two prices before it and two after it. Which position is that?
- Hint 2
Enter all five prices in one Desmos list, even though one price appears twice. Each observation comes from a different station. If you leave out a repeat, are you still finding the middle of five prices?
Step-by-step
Find the median with a Desmos list
Step 1Identify the middle position
Five station prices mean the median, the middle value after ordering the prices, is the third value. Two prices come before it and two come after it. The table’s third station row isn’t necessarily third by price.
- Step 2
Enter every recorded price
Type in Desmos, following the station rows. Desmos shows five entries, including both s. Repeated prices still count as separate observations when they come from separate stations.
- Step 3
Read the middle price
Type ; Desmos shows . In price order, the list is , so Desmos has selected the third price. The median gas price is $3.699. Choice C.