Finding the Fourth Proportional to 1,108.59, 1,529.94 and 636.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,108.59 : 1,529.94 = 636.50 : x
2. Step 2: Convert to fraction form
   1,108.59/1,529.94 = 636.50/x
3. Step 3: Cross multiply
   1,108.59x = 1,529.94 × 636.50
4. Step 4: Simplify right side
   1,108.59x = 973,799.16
5. Step 5: Solve for x
   x = 973,799.16/1,108.59
6. Step 6: Final answer
   x = 878.41