Finding the Third Proportional to 339,076 and 512,978.50

Step by Step Solution

1. Step 1: Write the proportion equation
   339,076 : 512,978.50 = 512,978.50 : x
2. Step 2: Convert to fraction form
   339,076/512,978.50 = 512,978.50/x
3. Step 3: Cross multiply
   339,076x = 512,978.50 × 512,978.50
4. Step 4: Simplify right side
   339,076x = 263,146,941,462.25
5. Step 5: Solve for x
   x = 263,146,941,462.25/339,076
6. Step 6: Final answer
   x = 776,070.68