Finding the Third Proportional to 139,433.50 and 286,215.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,433.50 : 286,215.50 = 286,215.50 : x
2. Step 2: Convert to fraction form
   139,433.50/286,215.50 = 286,215.50/x
3. Step 3: Cross multiply
   139,433.50x = 286,215.50 × 286,215.50
4. Step 4: Simplify right side
   139,433.50x = 81,919,312,440.25
5. Step 5: Solve for x
   x = 81,919,312,440.25/139,433.50
6. Step 6: Final answer
   x = 587,515.28