Finding the Fourth Proportional to 1,405.32, 1,939.24 and 1,142.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.32 : 1,939.24 = 1,142.88 : x
2. Step 2: Convert to fraction form
   1,405.32/1,939.24 = 1,142.88/x
3. Step 3: Cross multiply
   1,405.32x = 1,939.24 × 1,142.88
4. Step 4: Simplify right side
   1,405.32x = 2,216,318.61
5. Step 5: Solve for x
   x = 2,216,318.61/1,405.32
6. Step 6: Final answer
   x = 1,577.09