Finding the Third Proportional to 7,678.13 and 12,399.75

Step by Step Solution

1. Step 1: Write the proportion equation
   7,678.13 : 12,399.75 = 12,399.75 : x
2. Step 2: Convert to fraction form
   7,678.13/12,399.75 = 12,399.75/x
3. Step 3: Cross multiply
   7,678.13x = 12,399.75 × 12,399.75
4. Step 4: Simplify right side
   7,678.13x = 153,753,800.06
5. Step 5: Solve for x
   x = 153,753,800.06/7,678.13
6. Step 6: Final answer
   x = 20,024.91