Finding the Fourth Proportional to 139,401.91, 192,368.37 and 78,971.32

Step by Step Solution

1. Step 1: Write the proportion equation
   139,401.91 : 192,368.37 = 78,971.32 : x
2. Step 2: Convert to fraction form
   139,401.91/192,368.37 = 78,971.32/x
3. Step 3: Cross multiply
   139,401.91x = 192,368.37 × 78,971.32
4. Step 4: Simplify right side
   139,401.91x = 15,191,584,197.54
5. Step 5: Solve for x
   x = 15,191,584,197.54/139,401.91
6. Step 6: Final answer
   x = 108,976.87