Finding the Third Proportional to 90,643 and 199,410

Step by Step Solution

1. Step 1: Write the proportion equation
   90,643 : 199,410 = 199,410 : x
2. Step 2: Convert to fraction form
   90,643/199,410 = 199,410/x
3. Step 3: Cross multiply
   90,643x = 199,410 × 199,410
4. Step 4: Simplify right side
   90,643x = 39,764,348,100
5. Step 5: Solve for x
   x = 39,764,348,100/90,643
6. Step 6: Final answer
   x = 438,691.88