Finding the Fourth Proportional to 21,007.50, 28,990.47 and 14,643.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,007.50 : 28,990.47 = 14,643.42 : x
2. Step 2: Convert to fraction form
   21,007.50/28,990.47 = 14,643.42/x
3. Step 3: Cross multiply
   21,007.50x = 28,990.47 × 14,643.42
4. Step 4: Simplify right side
   21,007.50x = 424,519,628.21
5. Step 5: Solve for x
   x = 424,519,628.21/21,007.50
6. Step 6: Final answer
   x = 20,208.00