Finding the Third Proportional to 138,756 and 208,153.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,756 : 208,153.50 = 208,153.50 : x
2. Step 2: Convert to fraction form
   138,756/208,153.50 = 208,153.50/x
3. Step 3: Cross multiply
   138,756x = 208,153.50 × 208,153.50
4. Step 4: Simplify right side
   138,756x = 43,327,879,562.25
5. Step 5: Solve for x
   x = 43,327,879,562.25/138,756
6. Step 6: Final answer
   x = 312,259.50