Finding the Fourth Proportional to 1,142.31, 1,714.28 and 411.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.31 : 1,714.28 = 411.90 : x
2. Step 2: Convert to fraction form
   1,142.31/1,714.28 = 411.90/x
3. Step 3: Cross multiply
   1,142.31x = 1,714.28 × 411.90
4. Step 4: Simplify right side
   1,142.31x = 706,111.93
5. Step 5: Solve for x
   x = 706,111.93/1,142.31
6. Step 6: Final answer
   x = 618.14