Finding the Fourth Proportional to 21,320.76, 31,923.74 and 13,906.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,320.76 : 31,923.74 = 13,906.84 : x
2. Step 2: Convert to fraction form
   21,320.76/31,923.74 = 13,906.84/x
3. Step 3: Cross multiply
   21,320.76x = 31,923.74 × 13,906.84
4. Step 4: Simplify right side
   21,320.76x = 443,958,344.38
5. Step 5: Solve for x
   x = 443,958,344.38/21,320.76
6. Step 6: Final answer
   x = 20,822.82