Finding the Third Proportional to 138,726 and 207,709.31

Step by Step Solution

1. Step 1: Write the proportion equation
   138,726 : 207,709.31 = 207,709.31 : x
2. Step 2: Convert to fraction form
   138,726/207,709.31 = 207,709.31/x
3. Step 3: Cross multiply
   138,726x = 207,709.31 × 207,709.31
4. Step 4: Simplify right side
   138,726x = 43,143,158,499.22
5. Step 5: Solve for x
   x = 43,143,158,499.22/138,726
6. Step 6: Final answer
   x = 310,995.48