Finding the Fourth Proportional to 1,160.59, 1,601.61 and 636.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,160.59 : 1,601.61 = 636.61 : x
2. Step 2: Convert to fraction form
   1,160.59/1,601.61 = 636.61/x
3. Step 3: Cross multiply
   1,160.59x = 1,601.61 × 636.61
4. Step 4: Simplify right side
   1,160.59x = 1,019,600.94
5. Step 5: Solve for x
   x = 1,019,600.94/1,160.59
6. Step 6: Final answer
   x = 878.52