Finding the Fourth Proportional to 21,017.72, 31,499.33 and 8,523.15

Step by Step Solution

1. Step 1: Write the proportion equation
   21,017.72 : 31,499.33 = 8,523.15 : x
2. Step 2: Convert to fraction form
   21,017.72/31,499.33 = 8,523.15/x
3. Step 3: Cross multiply
   21,017.72x = 31,499.33 × 8,523.15
4. Step 4: Simplify right side
   21,017.72x = 268,473,471.87
5. Step 5: Solve for x
   x = 268,473,471.87/21,017.72
6. Step 6: Final answer
   x = 12,773.68