Finding the Fourth Proportional to 71,978.78, 107,229.44 and 68,740.32

Step by Step Solution

1. Step 1: Write the proportion equation
   71,978.78 : 107,229.44 = 68,740.32 : x
2. Step 2: Convert to fraction form
   71,978.78/107,229.44 = 68,740.32/x
3. Step 3: Cross multiply
   71,978.78x = 107,229.44 × 68,740.32
4. Step 4: Simplify right side
   71,978.78x = 7,370,985,675.32
5. Step 5: Solve for x
   x = 7,370,985,675.32/71,978.78
6. Step 6: Final answer
   x = 102,404.99