Finding the Fourth Proportional to 21,086.42, 31,668.51 and 16,731.86

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086.42 : 31,668.51 = 16,731.86 : x
2. Step 2: Convert to fraction form
   21,086.42/31,668.51 = 16,731.86/x
3. Step 3: Cross multiply
   21,086.42x = 31,668.51 × 16,731.86
4. Step 4: Simplify right side
   21,086.42x = 529,873,075.73
5. Step 5: Solve for x
   x = 529,873,075.73/21,086.42
6. Step 6: Final answer
   x = 25,128.64