Finding the Fourth Proportional to 1,152.31, 1,589.70 and 686.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.31 : 1,589.70 = 686.56 : x
2. Step 2: Convert to fraction form
   1,152.31/1,589.70 = 686.56/x
3. Step 3: Cross multiply
   1,152.31x = 1,589.70 × 686.56
4. Step 4: Simplify right side
   1,152.31x = 1,091,424.43
5. Step 5: Solve for x
   x = 1,091,424.43/1,152.31
6. Step 6: Final answer
   x = 947.16