Finding the Fourth Proportional to 1,139.93, 1,573.46 and 714.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.93 : 1,573.46 = 714.78 : x
2. Step 2: Convert to fraction form
   1,139.93/1,573.46 = 714.78/x
3. Step 3: Cross multiply
   1,139.93x = 1,573.46 × 714.78
4. Step 4: Simplify right side
   1,139.93x = 1,124,677.74
5. Step 5: Solve for x
   x = 1,124,677.74/1,139.93
6. Step 6: Final answer
   x = 986.62