Finding the Fourth Proportional to 1,133.61, 1,564.41 and 636.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,133.61 : 1,564.41 = 636.31 : x
2. Step 2: Convert to fraction form
   1,133.61/1,564.41 = 636.31/x
3. Step 3: Cross multiply
   1,133.61x = 1,564.41 × 636.31
4. Step 4: Simplify right side
   1,133.61x = 995,445.27
5. Step 5: Solve for x
   x = 995,445.27/1,133.61
6. Step 6: Final answer
   x = 878.12