Finding the Fourth Proportional to 139,042.57, 191,888.58 and 78,613.80

Step by Step Solution

1. Step 1: Write the proportion equation
   139,042.57 : 191,888.58 = 78,613.80 : x
2. Step 2: Convert to fraction form
   139,042.57/191,888.58 = 78,613.80/x
3. Step 3: Cross multiply
   139,042.57x = 191,888.58 × 78,613.80
4. Step 4: Simplify right side
   139,042.57x = 15,085,090,450.40
5. Step 5: Solve for x
   x = 15,085,090,450.40/139,042.57
6. Step 6: Final answer
   x = 108,492.60