Finding the Third Proportional to 378,978.50 and 821,697

Step by Step Solution

1. Step 1: Write the proportion equation
   378,978.50 : 821,697 = 821,697 : x
2. Step 2: Convert to fraction form
   378,978.50/821,697 = 821,697/x
3. Step 3: Cross multiply
   378,978.50x = 821,697 × 821,697
4. Step 4: Simplify right side
   378,978.50x = 675,185,959,809
5. Step 5: Solve for x
   x = 675,185,959,809/378,978.50
6. Step 6: Final answer
   x = 1,781,594.36