Finding the Fourth Proportional to 1,108.98, 1,530.38 and 636.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,108.98 : 1,530.38 = 636.89 : x
2. Step 2: Convert to fraction form
   1,108.98/1,530.38 = 636.89/x
3. Step 3: Cross multiply
   1,108.98x = 1,530.38 × 636.89
4. Step 4: Simplify right side
   1,108.98x = 974,672.88
5. Step 5: Solve for x
   x = 974,672.88/1,108.98
6. Step 6: Final answer
   x = 878.89