Finding the Fourth Proportional to 21,931.43, 30,268.78 and 14,399.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,931.43 : 30,268.78 = 14,399.61 : x
2. Step 2: Convert to fraction form
   21,931.43/30,268.78 = 14,399.61/x
3. Step 3: Cross multiply
   21,931.43x = 30,268.78 × 14,399.61
4. Step 4: Simplify right side
   21,931.43x = 435,858,627.18
5. Step 5: Solve for x
   x = 435,858,627.18/21,931.43
6. Step 6: Final answer
   x = 19,873.70