Finding the Fourth Proportional to 139,174.40, 208,672.80 and 91,734.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139,174.40 : 208,672.80 = 91,734.72 : x
2. Step 2: Convert to fraction form
   139,174.40/208,672.80 = 91,734.72/x
3. Step 3: Cross multiply
   139,174.40x = 208,672.80 × 91,734.72
4. Step 4: Simplify right side
   139,174.40x = 19,142,540,879.62
5. Step 5: Solve for x
   x = 19,142,540,879.62/139,174.40
6. Step 6: Final answer
   x = 137,543.55