Finding the Fourth Proportional to 42,505.56, 63,760.62 and 12,921.12

Step by Step Solution

1. Step 1: Write the proportion equation
   42,505.56 : 63,760.62 = 12,921.12 : x
2. Step 2: Convert to fraction form
   42,505.56/63,760.62 = 12,921.12/x
3. Step 3: Cross multiply
   42,505.56x = 63,760.62 × 12,921.12
4. Step 4: Simplify right side
   42,505.56x = 823,858,622.29
5. Step 5: Solve for x
   x = 823,858,622.29/42,505.56
6. Step 6: Final answer
   x = 19,382.37