Finding the Third Proportional to 138,411 and 207,616.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,411 : 207,616.50 = 207,616.50 : x
2. Step 2: Convert to fraction form
   138,411/207,616.50 = 207,616.50/x
3. Step 3: Cross multiply
   138,411x = 207,616.50 × 207,616.50
4. Step 4: Simplify right side
   138,411x = 43,104,611,072.25
5. Step 5: Solve for x
   x = 43,104,611,072.25/138,411
6. Step 6: Final answer
   x = 311,424.75