Finding the Third Proportional to 138,939 and 298,590

Step by Step Solution

1. Step 1: Write the proportion equation
   138,939 : 298,590 = 298,590 : x
2. Step 2: Convert to fraction form
   138,939/298,590 = 298,590/x
3. Step 3: Cross multiply
   138,939x = 298,590 × 298,590
4. Step 4: Simplify right side
   138,939x = 89,155,988,100
5. Step 5: Solve for x
   x = 89,155,988,100/138,939
6. Step 6: Final answer
   x = 641,691.59