Finding the Fourth Proportional to 71.94, 107.89 and 28.61

Step by Step Solution

1. Step 1: Write the proportion equation
   71.94 : 107.89 = 28.61 : x
2. Step 2: Convert to fraction form
   71.94/107.89 = 28.61/x
3. Step 3: Cross multiply
   71.94x = 107.89 × 28.61
4. Step 4: Simplify right side
   71.94x = 3,086.73
5. Step 5: Solve for x
   x = 3,086.73/71.94
6. Step 6: Final answer
   x = 42.91