Finding the Fourth Proportional to 21,879.72, 30,196.26 and 13,387.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,879.72 : 30,196.26 = 13,387.50 : x
2. Step 2: Convert to fraction form
   21,879.72/30,196.26 = 13,387.50/x
3. Step 3: Cross multiply
   21,879.72x = 30,196.26 × 13,387.50
4. Step 4: Simplify right side
   21,879.72x = 404,252,430.75
5. Step 5: Solve for x
   x = 404,252,430.75/21,879.72
6. Step 6: Final answer
   x = 18,476.12