Finding the Third Proportional to 7,705.50 and 12,405

Step by Step Solution

1. Step 1: Write the proportion equation
   7,705.50 : 12,405 = 12,405 : x
2. Step 2: Convert to fraction form
   7,705.50/12,405 = 12,405/x
3. Step 3: Cross multiply
   7,705.50x = 12,405 × 12,405
4. Step 4: Simplify right side
   7,705.50x = 153,884,025
5. Step 5: Solve for x
   x = 153,884,025/7,705.50
6. Step 6: Final answer
   x = 19,970.67