Finding the Fourth Proportional to 8,521.61, 12,787.34 and 3,590.87

Step by Step Solution

1. Step 1: Write the proportion equation
   8,521.61 : 12,787.34 = 3,590.87 : x
2. Step 2: Convert to fraction form
   8,521.61/12,787.34 = 3,590.87/x
3. Step 3: Cross multiply
   8,521.61x = 12,787.34 × 3,590.87
4. Step 4: Simplify right side
   8,521.61x = 45,917,593.69
5. Step 5: Solve for x
   x = 45,917,593.69/8,521.61
6. Step 6: Final answer
   x = 5,388.37