Finding the Third Proportional to 421,079.50 and 647,238

Step by Step Solution

1. Step 1: Write the proportion equation
   421,079.50 : 647,238 = 647,238 : x
2. Step 2: Convert to fraction form
   421,079.50/647,238 = 647,238/x
3. Step 3: Cross multiply
   421,079.50x = 647,238 × 647,238
4. Step 4: Simplify right side
   421,079.50x = 418,917,028,644
5. Step 5: Solve for x
   x = 418,917,028,644/421,079.50
6. Step 6: Final answer
   x = 994,864.46