Finding the Fourth Proportional to 28,238.28, 38,970.06 and 15,663

Step by Step Solution

1. Step 1: Write the proportion equation
   28,238.28 : 38,970.06 = 15,663 : x
2. Step 2: Convert to fraction form
   28,238.28/38,970.06 = 15,663/x
3. Step 3: Cross multiply
   28,238.28x = 38,970.06 × 15,663
4. Step 4: Simplify right side
   28,238.28x = 610,388,049.78
5. Step 5: Solve for x
   x = 610,388,049.78/28,238.28
6. Step 6: Final answer
   x = 21,615.62