Finding the Third Proportional to 515,723 and 788,408.75

Step by Step Solution

1. Step 1: Write the proportion equation
   515,723 : 788,408.75 = 788,408.75 : x
2. Step 2: Convert to fraction form
   515,723/788,408.75 = 788,408.75/x
3. Step 3: Cross multiply
   515,723x = 788,408.75 × 788,408.75
4. Step 4: Simplify right side
   515,723x = 621,588,357,076.56
5. Step 5: Solve for x
   x = 621,588,357,076.56/515,723
6. Step 6: Final answer
   x = 1,205,275.62