Finding the Fourth Proportional to 1,152.52, 1,590.50 and 686.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.52 : 1,590.50 = 686.78 : x
2. Step 2: Convert to fraction form
   1,152.52/1,590.50 = 686.78/x
3. Step 3: Cross multiply
   1,152.52x = 1,590.50 × 686.78
4. Step 4: Simplify right side
   1,152.52x = 1,092,323.59
5. Step 5: Solve for x
   x = 1,092,323.59/1,152.52
6. Step 6: Final answer
   x = 947.77