Finding the Third Proportional to 12,390 and 25,788

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390 : 25,788 = 25,788 : x
2. Step 2: Convert to fraction form
   12,390/25,788 = 25,788/x
3. Step 3: Cross multiply
   12,390x = 25,788 × 25,788
4. Step 4: Simplify right side
   12,390x = 665,020,944
5. Step 5: Solve for x
   x = 665,020,944/12,390
6. Step 6: Final answer
   x = 53,674.01