Finding the Fourth Proportional to 31,145.63, 42,966.02 and 20,385.76

Step by Step Solution

1. Step 1: Write the proportion equation
   31,145.63 : 42,966.02 = 20,385.76 : x
2. Step 2: Convert to fraction form
   31,145.63/42,966.02 = 20,385.76/x
3. Step 3: Cross multiply
   31,145.63x = 42,966.02 × 20,385.76
4. Step 4: Simplify right side
   31,145.63x = 875,894,971.88
5. Step 5: Solve for x
   x = 875,894,971.88/31,145.63
6. Step 6: Final answer
   x = 28,122.56