Finding the Third Proportional to 144,585 and 320,139

Step by Step Solution

1. Step 1: Write the proportion equation
   144,585 : 320,139 = 320,139 : x
2. Step 2: Convert to fraction form
   144,585/320,139 = 320,139/x
3. Step 3: Cross multiply
   144,585x = 320,139 × 320,139
4. Step 4: Simplify right side
   144,585x = 102,488,979,321
5. Step 5: Solve for x
   x = 102,488,979,321/144,585
6. Step 6: Final answer
   x = 708,849.32