Finding the Fourth Proportional to 13,145.91, 19,723.52 and 8,209.86

Step by Step Solution

1. Step 1: Write the proportion equation
   13,145.91 : 19,723.52 = 8,209.86 : x
2. Step 2: Convert to fraction form
   13,145.91/19,723.52 = 8,209.86/x
3. Step 3: Cross multiply
   13,145.91x = 19,723.52 × 8,209.86
4. Step 4: Simplify right side
   13,145.91x = 161,927,337.91
5. Step 5: Solve for x
   x = 161,927,337.91/13,145.91
6. Step 6: Final answer
   x = 12,317.70