Finding the Fourth Proportional to 1,080.17, 1,490.88 and 638.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.17 : 1,490.88 = 638.22 : x
2. Step 2: Convert to fraction form
   1,080.17/1,490.88 = 638.22/x
3. Step 3: Cross multiply
   1,080.17x = 1,490.88 × 638.22
4. Step 4: Simplify right side
   1,080.17x = 951,509.43
5. Step 5: Solve for x
   x = 951,509.43/1,080.17
6. Step 6: Final answer
   x = 880.89