Ricardo ran a very unusual course. One hundred (100) people (reporters) stood along the track at various distances from the start. The only information each person had was the length (in km) of his or her segment. When Ricardo passed the end of a segment, the reporter for that segment relayed the information that Ricardo had run the length of that segment.

Reported distances are in a table in the Graphing Calculator (GC) file linked below, in the column labeled **D**. To represent (access) an entry, such as **D**_{12}, type

**D** ctrl-L 12 $\rightarrow$.

Typing ctrl-L puts GC in subscript mode. Pressing $\rightarrow$ causes the cursor to move to the next element in the expression, or to the end.

Reminders:

- Type ctrl-L for a subscript
- Press "$\rightarrow$" to escape an exponent, subscript, or move to the next element in an expression.
- Type "*" for multiplication, "/" for division, "+" for addition, "-" for subtraction or negation, and "^" for exponent
- Type ctrl-shift-S for a summation sign ($\sum$)

Download *Ricardo1 * and define functions to represent values of quantities described in it.