Finding the Third Proportional to 543,138.56 and 821,697

Step by Step Solution

1. Step 1: Write the proportion equation
   543,138.56 : 821,697 = 821,697 : x
2. Step 2: Convert to fraction form
   543,138.56/821,697 = 821,697/x
3. Step 3: Cross multiply
   543,138.56x = 821,697 × 821,697
4. Step 4: Simplify right side
   543,138.56x = 675,185,959,809
5. Step 5: Solve for x
   x = 675,185,959,809/543,138.56
6. Step 6: Final answer
   x = 1,243,119.17