Finding the Third Proportional to 280,300 and 402,918

Step by Step Solution

1. Step 1: Write the proportion equation
   280,300 : 402,918 = 402,918 : x
2. Step 2: Convert to fraction form
   280,300/402,918 = 402,918/x
3. Step 3: Cross multiply
   280,300x = 402,918 × 402,918
4. Step 4: Simplify right side
   280,300x = 162,342,914,724
5. Step 5: Solve for x
   x = 162,342,914,724/280,300
6. Step 6: Final answer
   x = 579,175.58