Finding the Fourth Proportional to 13,558.42, 18,717.78 and 8,785.18

Step by Step Solution

1. Step 1: Write the proportion equation
   13,558.42 : 18,717.78 = 8,785.18 : x
2. Step 2: Convert to fraction form
   13,558.42/18,717.78 = 8,785.18/x
3. Step 3: Cross multiply
   13,558.42x = 18,717.78 × 8,785.18
4. Step 4: Simplify right side
   13,558.42x = 164,439,066.50
5. Step 5: Solve for x
   x = 164,439,066.50/13,558.42
6. Step 6: Final answer
   x = 12,128.19