Finding the Fourth Proportional to 91,978.70, 137,968.05 and 76,426.70

Step by Step Solution

1. Step 1: Write the proportion equation
   91,978.70 : 137,968.05 = 76,426.70 : x
2. Step 2: Convert to fraction form
   91,978.70/137,968.05 = 76,426.70/x
3. Step 3: Cross multiply
   91,978.70x = 137,968.05 × 76,426.70
4. Step 4: Simplify right side
   91,978.70x = 10,544,442,766.94
5. Step 5: Solve for x
   x = 10,544,442,766.94/91,978.70
6. Step 6: Final answer
   x = 114,640.05