Finding the Third Proportional to 138,708 and 208,858.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,708 : 208,858.50 = 208,858.50 : x
2. Step 2: Convert to fraction form
   138,708/208,858.50 = 208,858.50/x
3. Step 3: Cross multiply
   138,708x = 208,858.50 × 208,858.50
4. Step 4: Simplify right side
   138,708x = 43,621,873,022.25
5. Step 5: Solve for x
   x = 43,621,873,022.25/138,708
6. Step 6: Final answer
   x = 314,487.07