Finding the Fourth Proportional to 21,577.32, 29,779.54 and 12,147.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,577.32 : 29,779.54 = 12,147.72 : x
2. Step 2: Convert to fraction form
   21,577.32/29,779.54 = 12,147.72/x
3. Step 3: Cross multiply
   21,577.32x = 29,779.54 × 12,147.72
4. Step 4: Simplify right side
   21,577.32x = 361,753,513.65
5. Step 5: Solve for x
   x = 361,753,513.65/21,577.32
6. Step 6: Final answer
   x = 16,765.45