Finding the Third Proportional to 688 and 1,030.50

Step by Step Solution

1. Step 1: Write the proportion equation
   688 : 1,030.50 = 1,030.50 : x
2. Step 2: Convert to fraction form
   688/1,030.50 = 1,030.50/x
3. Step 3: Cross multiply
   688x = 1,030.50 × 1,030.50
4. Step 4: Simplify right side
   688x = 1,061,930.25
5. Step 5: Solve for x
   x = 1,061,930.25/688
6. Step 6: Final answer
   x = 1,543.50