Finding the Third Proportional to 5,128,585 and 8,120,984

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128,585 : 8,120,984 = 8,120,984 : x
2. Step 2: Convert to fraction form
   5,128,585/8,120,984 = 8,120,984/x
3. Step 3: Cross multiply
   5,128,585x = 8,120,984 × 8,120,984
4. Step 4: Simplify right side
   5,128,585x = 65,950,381,128,256
5. Step 5: Solve for x
   x = 65,950,381,128,256/5,128,585
6. Step 6: Final answer
   x = 12,859,371.76