Finding the Fourth Proportional to 21,006.02, 28,988.88 and 12,942.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,006.02 : 28,988.88 = 12,942.38 : x
2. Step 2: Convert to fraction form
   21,006.02/28,988.88 = 12,942.38/x
3. Step 3: Cross multiply
   21,006.02x = 28,988.88 × 12,942.38
4. Step 4: Simplify right side
   21,006.02x = 375,185,100.73
5. Step 5: Solve for x
   x = 375,185,100.73/21,006.02
6. Step 6: Final answer
   x = 17,860.84