Finding the Fourth Proportional to 13,326.72, 18,390.72 and 9,136.32

Step by Step Solution

1. Step 1: Write the proportion equation
   13,326.72 : 18,390.72 = 9,136.32 : x
2. Step 2: Convert to fraction form
   13,326.72/18,390.72 = 9,136.32/x
3. Step 3: Cross multiply
   13,326.72x = 18,390.72 × 9,136.32
4. Step 4: Simplify right side
   13,326.72x = 168,023,502.95
5. Step 5: Solve for x
   x = 168,023,502.95/13,326.72
6. Step 6: Final answer
   x = 12,608.02