Finding the Fourth Proportional to 21,142.84, 31,691.34 and 13,752.58

Step by Step Solution

1. Step 1: Write the proportion equation
   21,142.84 : 31,691.34 = 13,752.58 : x
2. Step 2: Convert to fraction form
   21,142.84/31,691.34 = 13,752.58/x
3. Step 3: Cross multiply
   21,142.84x = 31,691.34 × 13,752.58
4. Step 4: Simplify right side
   21,142.84x = 435,837,688.66
5. Step 5: Solve for x
   x = 435,837,688.66/21,142.84
6. Step 6: Final answer
   x = 20,613.96