Finding the Third Proportional to 386,922 and 516,037.50

Step by Step Solution

1. Step 1: Write the proportion equation
   386,922 : 516,037.50 = 516,037.50 : x
2. Step 2: Convert to fraction form
   386,922/516,037.50 = 516,037.50/x
3. Step 3: Cross multiply
   386,922x = 516,037.50 × 516,037.50
4. Step 4: Simplify right side
   386,922x = 266,294,701,406.25
5. Step 5: Solve for x
   x = 266,294,701,406.25/386,922
6. Step 6: Final answer
   x = 688,238.72