A table with one count for each day calls for the median when the question asks for the middle daily count. With an odd number of days, find the middle position after ordering the counts. A Desmos list and median will do the ordering while keeping repeated values. Reading the middle day instead confuses time order with value order.
Hints
- Hint 1
The median is the middle value after you arrange the daily counts from least to greatest. The table's day order tells you when Amy mailed postcards, not how the counts rank.
- Hint 2
With nine values, the fifth position has four values on either side. Put every day's count into a Desmos list, including repeats, then ask for its median.
Step-by-step
Use a Desmos list to find the middle
Step 1Locate the middle position
The median is the middle value once the counts are in order. With days, four counts sit on each side of the middle, so its position is . Sort by postcards mailed, not by day number. The fifth day need not have the fifth-smallest count.
- Step 2
Enter all nine daily counts
Read the Postcards mailed row from day through day . Type in Desmos. The list keeps every day's count, including repeats; Desmos now holds all values in .
- Step 3
Read the middle count
Type . Desmos shows : in order, the counts are , and the fifth value is . Amy mailed a median of postcards per day. Choice B.