Finding the Third Proportional to 1,121.98 and 1,680.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,121.98 : 1,680.12 = 1,680.12 : x
2. Step 2: Convert to fraction form
   1,121.98/1,680.12 = 1,680.12/x
3. Step 3: Cross multiply
   1,121.98x = 1,680.12 × 1,680.12
4. Step 4: Simplify right side
   1,121.98x = 2,822,793.76
5. Step 5: Solve for x
   x = 2,822,793.76/1,121.98
6. Step 6: Final answer
   x = 2,515.91