Finding the Third Proportional to 155,308.50 and 339,691.50

Step by Step Solution

1. Step 1: Write the proportion equation
   155,308.50 : 339,691.50 = 339,691.50 : x
2. Step 2: Convert to fraction form
   155,308.50/339,691.50 = 339,691.50/x
3. Step 3: Cross multiply
   155,308.50x = 339,691.50 × 339,691.50
4. Step 4: Simplify right side
   155,308.50x = 115,390,315,172.25
5. Step 5: Solve for x
   x = 115,390,315,172.25/155,308.50
6. Step 6: Final answer
   x = 742,974.89