Finding the Fourth Proportional to 21,086.91, 31,614.73 and 12,764.96

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086.91 : 31,614.73 = 12,764.96 : x
2. Step 2: Convert to fraction form
   21,086.91/31,614.73 = 12,764.96/x
3. Step 3: Cross multiply
   21,086.91x = 31,614.73 × 12,764.96
4. Step 4: Simplify right side
   21,086.91x = 403,560,728.33
5. Step 5: Solve for x
   x = 403,560,728.33/21,086.91
6. Step 6: Final answer
   x = 19,137.98