Finding the Fourth Proportional to 13,158.86, 18,162.43 and 8,690.09

Step by Step Solution

1. Step 1: Write the proportion equation
   13,158.86 : 18,162.43 = 8,690.09 : x
2. Step 2: Convert to fraction form
   13,158.86/18,162.43 = 8,690.09/x
3. Step 3: Cross multiply
   13,158.86x = 18,162.43 × 8,690.09
4. Step 4: Simplify right side
   13,158.86x = 157,833,038.78
5. Step 5: Solve for x
   x = 157,833,038.78/13,158.86
6. Step 6: Final answer
   x = 11,994.44