Finding the Fourth Proportional to 21,009.38, 28,991.15 and 12,056.69

Step by Step Solution

1. Step 1: Write the proportion equation
   21,009.38 : 28,991.15 = 12,056.69 : x
2. Step 2: Convert to fraction form
   21,009.38/28,991.15 = 12,056.69/x
3. Step 3: Cross multiply
   21,009.38x = 28,991.15 × 12,056.69
4. Step 4: Simplify right side
   21,009.38x = 349,537,410.91
5. Step 5: Solve for x
   x = 349,537,410.91/21,009.38
6. Step 6: Final answer
   x = 16,637.21