Finding the Fourth Proportional to 1,152.70, 1,590.56 and 680.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.70 : 1,590.56 = 680.61 : x
2. Step 2: Convert to fraction form
   1,152.70/1,590.56 = 680.61/x
3. Step 3: Cross multiply
   1,152.70x = 1,590.56 × 680.61
4. Step 4: Simplify right side
   1,152.70x = 1,082,551.04
5. Step 5: Solve for x
   x = 1,082,551.04/1,152.70
6. Step 6: Final answer
   x = 939.14