Finding the Fourth Proportional to 21,002.72, 31,509.92 and 9,157.53

Step by Step Solution

1. Step 1: Write the proportion equation
   21,002.72 : 31,509.92 = 9,157.53 : x
2. Step 2: Convert to fraction form
   21,002.72/31,509.92 = 9,157.53/x
3. Step 3: Cross multiply
   21,002.72x = 31,509.92 × 9,157.53
4. Step 4: Simplify right side
   21,002.72x = 288,553,060.59
5. Step 5: Solve for x
   x = 288,553,060.59/21,002.72
6. Step 6: Final answer
   x = 13,738.84