Finding the Fourth Proportional to 1,152.63, 1,590.81 and 687.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.63 : 1,590.81 = 687.15 : x
2. Step 2: Convert to fraction form
   1,152.63/1,590.81 = 687.15/x
3. Step 3: Cross multiply
   1,152.63x = 1,590.81 × 687.15
4. Step 4: Simplify right side
   1,152.63x = 1,093,125.09
5. Step 5: Solve for x
   x = 1,093,125.09/1,152.63
6. Step 6: Final answer
   x = 948.37