Finding the Fourth Proportional to 139,016.12, 208,559.21 and 64,188.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139,016.12 : 208,559.21 = 64,188.72 : x
2. Step 2: Convert to fraction form
   139,016.12/208,559.21 = 64,188.72/x
3. Step 3: Cross multiply
   139,016.12x = 208,559.21 × 64,188.72
4. Step 4: Simplify right side
   139,016.12x = 13,387,148,413.17
5. Step 5: Solve for x
   x = 13,387,148,413.17/139,016.12
6. Step 6: Final answer
   x = 96,299.26