Finding the Fourth Proportional to 1,128.69, 1,557.78 and 1,099.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.69 : 1,557.78 = 1,099.08 : x
2. Step 2: Convert to fraction form
   1,128.69/1,557.78 = 1,099.08/x
3. Step 3: Cross multiply
   1,128.69x = 1,557.78 × 1,099.08
4. Step 4: Simplify right side
   1,128.69x = 1,712,124.84
5. Step 5: Solve for x
   x = 1,712,124.84/1,128.69
6. Step 6: Final answer
   x = 1,516.91