Finding the Fourth Proportional to 1,152.59, 1,590.59 and 686.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.59 : 1,590.59 = 686.75 : x
2. Step 2: Convert to fraction form
   1,152.59/1,590.59 = 686.75/x
3. Step 3: Cross multiply
   1,152.59x = 1,590.59 × 686.75
4. Step 4: Simplify right side
   1,152.59x = 1,092,337.68
5. Step 5: Solve for x
   x = 1,092,337.68/1,152.59
6. Step 6: Final answer
   x = 947.72