Finding the Third Proportional to 139,538 and 286,420

Step by Step Solution

1. Step 1: Write the proportion equation
   139,538 : 286,420 = 286,420 : x
2. Step 2: Convert to fraction form
   139,538/286,420 = 286,420/x
3. Step 3: Cross multiply
   139,538x = 286,420 × 286,420
4. Step 4: Simplify right side
   139,538x = 82,036,416,400
5. Step 5: Solve for x
   x = 82,036,416,400/139,538
6. Step 6: Final answer
   x = 587,914.52