Finding the Fourth Proportional to 1,131.81, 1,563.90 and 872.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.81 : 1,563.90 = 872.07 : x
2. Step 2: Convert to fraction form
   1,131.81/1,563.90 = 872.07/x
3. Step 3: Cross multiply
   1,131.81x = 1,563.90 × 872.07
4. Step 4: Simplify right side
   1,131.81x = 1,363,830.27
5. Step 5: Solve for x
   x = 1,363,830.27/1,131.81
6. Step 6: Final answer
   x = 1,205.00