Finding the Fourth Proportional to 42,855.89, 64,293.21 and 12,868.88

Step by Step Solution

1. Step 1: Write the proportion equation
   42,855.89 : 64,293.21 = 12,868.88 : x
2. Step 2: Convert to fraction form
   42,855.89/64,293.21 = 12,868.88/x
3. Step 3: Cross multiply
   42,855.89x = 64,293.21 × 12,868.88
4. Step 4: Simplify right side
   42,855.89x = 827,381,604.30
5. Step 5: Solve for x
   x = 827,381,604.30/42,855.89
6. Step 6: Final answer
   x = 19,306.14