Finding the Fourth Proportional to 1,399.54, 1,929.78 and 1,105.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.54 : 1,929.78 = 1,105.50 : x
2. Step 2: Convert to fraction form
   1,399.54/1,929.78 = 1,105.50/x
3. Step 3: Cross multiply
   1,399.54x = 1,929.78 × 1,105.50
4. Step 4: Simplify right side
   1,399.54x = 2,133,371.79
5. Step 5: Solve for x
   x = 2,133,371.79/1,399.54
6. Step 6: Final answer
   x = 1,524.34