Finding the Third Proportional to 138,403.50 and 206,884.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,403.50 : 206,884.50 = 206,884.50 : x
2. Step 2: Convert to fraction form
   138,403.50/206,884.50 = 206,884.50/x
3. Step 3: Cross multiply
   138,403.50x = 206,884.50 × 206,884.50
4. Step 4: Simplify right side
   138,403.50x = 42,801,196,340.25
5. Step 5: Solve for x
   x = 42,801,196,340.25/138,403.50
6. Step 6: Final answer
   x = 309,249.38