Finding the Third Proportional to 138,423 and 207,631.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,423 : 207,631.50 = 207,631.50 : x
2. Step 2: Convert to fraction form
   138,423/207,631.50 = 207,631.50/x
3. Step 3: Cross multiply
   138,423x = 207,631.50 × 207,631.50
4. Step 4: Simplify right side
   138,423x = 43,110,839,792.25
5. Step 5: Solve for x
   x = 43,110,839,792.25/138,423
6. Step 6: Final answer
   x = 311,442.75