Finding the Fourth Proportional to 42,800.18, 64,215.45 and 19,105.56

Step by Step Solution

1. Step 1: Write the proportion equation
   42,800.18 : 64,215.45 = 19,105.56 : x
2. Step 2: Convert to fraction form
   42,800.18/64,215.45 = 19,105.56/x
3. Step 3: Cross multiply
   42,800.18x = 64,215.45 × 19,105.56
4. Step 4: Simplify right side
   42,800.18x = 1,226,872,132.90
5. Step 5: Solve for x
   x = 1,226,872,132.90/42,800.18
6. Step 6: Final answer
   x = 28,665.12