Finding the Fourth Proportional to 1,390.92, 1,921.15 and 1,100.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.92 : 1,921.15 = 1,100.04 : x
2. Step 2: Convert to fraction form
   1,390.92/1,921.15 = 1,100.04/x
3. Step 3: Cross multiply
   1,390.92x = 1,921.15 × 1,100.04
4. Step 4: Simplify right side
   1,390.92x = 2,113,341.85
5. Step 5: Solve for x
   x = 2,113,341.85/1,390.92
6. Step 6: Final answer
   x = 1,519.38