Finding the Fourth Proportional to 13,518.90, 18,662.81 and 8,490.42

Step by Step Solution

1. Step 1: Write the proportion equation
   13,518.90 : 18,662.81 = 8,490.42 : x
2. Step 2: Convert to fraction form
   13,518.90/18,662.81 = 8,490.42/x
3. Step 3: Cross multiply
   13,518.90x = 18,662.81 × 8,490.42
4. Step 4: Simplify right side
   13,518.90x = 158,455,052.83
5. Step 5: Solve for x
   x = 158,455,052.83/13,518.90
6. Step 6: Final answer
   x = 11,721.00