Finding the Third Proportional to 5,128,788 and 8,121,312

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128,788 : 8,121,312 = 8,121,312 : x
2. Step 2: Convert to fraction form
   5,128,788/8,121,312 = 8,121,312/x
3. Step 3: Cross multiply
   5,128,788x = 8,121,312 × 8,121,312
4. Step 4: Simplify right side
   5,128,788x = 65,955,708,601,344
5. Step 5: Solve for x
   x = 65,955,708,601,344/5,128,788
6. Step 6: Final answer
   x = 12,859,901.52