Finding the Fourth Proportional to 31,815.21, 43,875.67 and 21,621.46

Step by Step Solution

1. Step 1: Write the proportion equation
   31,815.21 : 43,875.67 = 21,621.46 : x
2. Step 2: Convert to fraction form
   31,815.21/43,875.67 = 21,621.46/x
3. Step 3: Cross multiply
   31,815.21x = 43,875.67 × 21,621.46
4. Step 4: Simplify right side
   31,815.21x = 948,656,043.88
5. Step 5: Solve for x
   x = 948,656,043.88/31,815.21
6. Step 6: Final answer
   x = 29,817.69