Finding the Fourth Proportional to 21,454.32, 29,579.58 and 13,887.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,454.32 : 29,579.58 = 13,887.30 : x
2. Step 2: Convert to fraction form
   21,454.32/29,579.58 = 13,887.30/x
3. Step 3: Cross multiply
   21,454.32x = 29,579.58 × 13,887.30
4. Step 4: Simplify right side
   21,454.32x = 410,780,501.33
5. Step 5: Solve for x
   x = 410,780,501.33/21,454.32
6. Step 6: Final answer
   x = 19,146.75