Finding the Fourth Proportional to 21,647.50, 29,873.55 and 12,215.86

Step by Step Solution

1. Step 1: Write the proportion equation
   21,647.50 : 29,873.55 = 12,215.86 : x
2. Step 2: Convert to fraction form
   21,647.50/29,873.55 = 12,215.86/x
3. Step 3: Cross multiply
   21,647.50x = 29,873.55 × 12,215.86
4. Step 4: Simplify right side
   21,647.50x = 364,931,104.50
5. Step 5: Solve for x
   x = 364,931,104.50/21,647.50
6. Step 6: Final answer
   x = 16,857.89