Finding the Fourth Proportional to 1,181.78, 1,760.55 and 1,128.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,181.78 : 1,760.55 = 1,128.48 : x
2. Step 2: Convert to fraction form
   1,181.78/1,760.55 = 1,128.48/x
3. Step 3: Cross multiply
   1,181.78x = 1,760.55 × 1,128.48
4. Step 4: Simplify right side
   1,181.78x = 1,986,737.80
5. Step 5: Solve for x
   x = 1,986,737.80/1,181.78
6. Step 6: Final answer
   x = 1,681.13