Finding the Fourth Proportional to 1,139.27, 1,707.50 and 618.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.27 : 1,707.50 = 618.93 : x
2. Step 2: Convert to fraction form
   1,139.27/1,707.50 = 618.93/x
3. Step 3: Cross multiply
   1,139.27x = 1,707.50 × 618.93
4. Step 4: Simplify right side
   1,139.27x = 1,056,824.52
5. Step 5: Solve for x
   x = 1,056,824.52/1,139.27
6. Step 6: Final answer
   x = 927.64