Finding the Fourth Proportional to 1,131.24, 1,686.81 and 1,129.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.24 : 1,686.81 = 1,129.16 : x
2. Step 2: Convert to fraction form
   1,131.24/1,686.81 = 1,129.16/x
3. Step 3: Cross multiply
   1,131.24x = 1,686.81 × 1,129.16
4. Step 4: Simplify right side
   1,131.24x = 1,904,678.38
5. Step 5: Solve for x
   x = 1,904,678.38/1,131.24
6. Step 6: Final answer
   x = 1,683.71