Finding the Fourth Proportional to 79,978.78, 120,040.87 and 42,570.15

Step by Step Solution

1. Step 1: Write the proportion equation
   79,978.78 : 120,040.87 = 42,570.15 : x
2. Step 2: Convert to fraction form
   79,978.78/120,040.87 = 42,570.15/x
3. Step 3: Cross multiply
   79,978.78x = 120,040.87 × 42,570.15
4. Step 4: Simplify right side
   79,978.78x = 5,110,157,842.03
5. Step 5: Solve for x
   x = 5,110,157,842.03/79,978.78
6. Step 6: Final answer
   x = 63,893.92