Finding the Fourth Proportional to 42,567.85, 63,858.79 and 12,978.77

Step by Step Solution

1. Step 1: Write the proportion equation
   42,567.85 : 63,858.79 = 12,978.77 : x
2. Step 2: Convert to fraction form
   42,567.85/63,858.79 = 12,978.77/x
3. Step 3: Cross multiply
   42,567.85x = 63,858.79 × 12,978.77
4. Step 4: Simplify right side
   42,567.85x = 828,808,547.89
5. Step 5: Solve for x
   x = 828,808,547.89/42,567.85
6. Step 6: Final answer
   x = 19,470.29