Finding the Fourth Proportional to 1,080.88, 1,491.82 and 638.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.88 : 1,491.82 = 638.82 : x
2. Step 2: Convert to fraction form
   1,080.88/1,491.82 = 638.82/x
3. Step 3: Cross multiply
   1,080.88x = 1,491.82 × 638.82
4. Step 4: Simplify right side
   1,080.88x = 953,002.86
5. Step 5: Solve for x
   x = 953,002.86/1,080.88
6. Step 6: Final answer
   x = 881.69