Finding the Third Proportional to 305,143.50 and 638,172

Step by Step Solution

1. Step 1: Write the proportion equation
   305,143.50 : 638,172 = 638,172 : x
2. Step 2: Convert to fraction form
   305,143.50/638,172 = 638,172/x
3. Step 3: Cross multiply
   305,143.50x = 638,172 × 638,172
4. Step 4: Simplify right side
   305,143.50x = 407,263,501,584
5. Step 5: Solve for x
   x = 407,263,501,584/305,143.50
6. Step 6: Final answer
   x = 1,334,662.22