Finding the Fourth Proportional to 139,152.42, 192,030.39 and 78,721.86

Step by Step Solution

1. Step 1: Write the proportion equation
   139,152.42 : 192,030.39 = 78,721.86 : x
2. Step 2: Convert to fraction form
   139,152.42/192,030.39 = 78,721.86/x
3. Step 3: Cross multiply
   139,152.42x = 192,030.39 × 78,721.86
4. Step 4: Simplify right side
   139,152.42x = 15,116,989,477.33
5. Step 5: Solve for x
   x = 15,116,989,477.33/139,152.42
6. Step 6: Final answer
   x = 108,636.20