Finding the Fourth Proportional to 1,399.86, 1,934.28 and 1,107.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.86 : 1,934.28 = 1,107.45 : x
2. Step 2: Convert to fraction form
   1,399.86/1,934.28 = 1,107.45/x
3. Step 3: Cross multiply
   1,399.86x = 1,934.28 × 1,107.45
4. Step 4: Simplify right side
   1,399.86x = 2,142,118.39
5. Step 5: Solve for x
   x = 2,142,118.39/1,399.86
6. Step 6: Final answer
   x = 1,530.24