Finding the Third Proportional to 66,603 and 142,705.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66,603 : 142,705.50 = 142,705.50 : x
2. Step 2: Convert to fraction form
   66,603/142,705.50 = 142,705.50/x
3. Step 3: Cross multiply
   66,603x = 142,705.50 × 142,705.50
4. Step 4: Simplify right side
   66,603x = 20,364,859,730.25
5. Step 5: Solve for x
   x = 20,364,859,730.25/66,603
6. Step 6: Final answer
   x = 305,764.90