Finding the Fourth Proportional to 1,142.86, 1,577.15 and 618.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.86 : 1,577.15 = 618.89 : x
2. Step 2: Convert to fraction form
   1,142.86/1,577.15 = 618.89/x
3. Step 3: Cross multiply
   1,142.86x = 1,577.15 × 618.89
4. Step 4: Simplify right side
   1,142.86x = 976,080.83
5. Step 5: Solve for x
   x = 976,080.83/1,142.86
6. Step 6: Final answer
   x = 854.07