Finding the Third Proportional to 246,728 and 390,300

Step by Step Solution

1. Step 1: Write the proportion equation
   246,728 : 390,300 = 390,300 : x
2. Step 2: Convert to fraction form
   246,728/390,300 = 390,300/x
3. Step 3: Cross multiply
   246,728x = 390,300 × 390,300
4. Step 4: Simplify right side
   246,728x = 152,334,090,000
5. Step 5: Solve for x
   x = 152,334,090,000/246,728
6. Step 6: Final answer
   x = 617,417.12