Finding the Fourth Proportional to 139,978.43, 193,161.90 and 79,540.68

Step by Step Solution

1. Step 1: Write the proportion equation
   139,978.43 : 193,161.90 = 79,540.68 : x
2. Step 2: Convert to fraction form
   139,978.43/193,161.90 = 79,540.68/x
3. Step 3: Cross multiply
   139,978.43x = 193,161.90 × 79,540.68
4. Step 4: Simplify right side
   139,978.43x = 15,364,228,876.09
5. Step 5: Solve for x
   x = 15,364,228,876.09/139,978.43
6. Step 6: Final answer
   x = 109,761.40