Finding the Fourth Proportional to 8,585.16, 12,871.62 and 3,315.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,585.16 : 12,871.62 = 3,315.72 : x
2. Step 2: Convert to fraction form
   8,585.16/12,871.62 = 3,315.72/x
3. Step 3: Cross multiply
   8,585.16x = 12,871.62 × 3,315.72
4. Step 4: Simplify right side
   8,585.16x = 42,678,687.87
5. Step 5: Solve for x
   x = 42,678,687.87/8,585.16
6. Step 6: Final answer
   x = 4,971.22