Finding the Fourth Proportional to 21,002.98, 28,988.31 and 12,056.53

Step by Step Solution

1. Step 1: Write the proportion equation
   21,002.98 : 28,988.31 = 12,056.53 : x
2. Step 2: Convert to fraction form
   21,002.98/28,988.31 = 12,056.53/x
3. Step 3: Cross multiply
   21,002.98x = 28,988.31 × 12,056.53
4. Step 4: Simplify right side
   21,002.98x = 349,498,429.16
5. Step 5: Solve for x
   x = 349,498,429.16/21,002.98
6. Step 6: Final answer
   x = 16,640.42