Finding the Fourth Proportional to 42,560.42, 63,850.97 and 12,978.78

Step by Step Solution

1. Step 1: Write the proportion equation
   42,560.42 : 63,850.97 = 12,978.78 : x
2. Step 2: Convert to fraction form
   42,560.42/63,850.97 = 12,978.78/x
3. Step 3: Cross multiply
   42,560.42x = 63,850.97 × 12,978.78
4. Step 4: Simplify right side
   42,560.42x = 828,707,692.42
5. Step 5: Solve for x
   x = 828,707,692.42/42,560.42
6. Step 6: Final answer
   x = 19,471.32