Finding the Fourth Proportional to 42,387.77, 63,578.72 and 12,805.76

Step by Step Solution

1. Step 1: Write the proportion equation
   42,387.77 : 63,578.72 = 12,805.76 : x
2. Step 2: Convert to fraction form
   42,387.77/63,578.72 = 12,805.76/x
3. Step 3: Cross multiply
   42,387.77x = 63,578.72 × 12,805.76
4. Step 4: Simplify right side
   42,387.77x = 814,174,020.39
5. Step 5: Solve for x
   x = 814,174,020.39/42,387.77
6. Step 6: Final answer
   x = 19,207.76