Finding the Third Proportional to 142,788 and 317,490

Step by Step Solution

1. Step 1: Write the proportion equation
   142,788 : 317,490 = 317,490 : x
2. Step 2: Convert to fraction form
   142,788/317,490 = 317,490/x
3. Step 3: Cross multiply
   142,788x = 317,490 × 317,490
4. Step 4: Simplify right side
   142,788x = 100,799,900,100
5. Step 5: Solve for x
   x = 100,799,900,100/142,788
6. Step 6: Final answer
   x = 705,940.98