Finding the Fourth Proportional to 42,105.72, 63,147.78 and 12,515.88

Step by Step Solution

1. Step 1: Write the proportion equation
   42,105.72 : 63,147.78 = 12,515.88 : x
2. Step 2: Convert to fraction form
   42,105.72/63,147.78 = 12,515.88/x
3. Step 3: Cross multiply
   42,105.72x = 63,147.78 × 12,515.88
4. Step 4: Simplify right side
   42,105.72x = 790,350,036.75
5. Step 5: Solve for x
   x = 790,350,036.75/42,105.72
6. Step 6: Final answer
   x = 18,770.61