Finding the Fourth Proportional to 127.43, 191.18 and 54.31

Step by Step Solution

1. Step 1: Write the proportion equation
   127.43 : 191.18 = 54.31 : x
2. Step 2: Convert to fraction form
   127.43/191.18 = 54.31/x
3. Step 3: Cross multiply
   127.43x = 191.18 × 54.31
4. Step 4: Simplify right side
   127.43x = 10,383.12
5. Step 5: Solve for x
   x = 10,383.12/127.43
6. Step 6: Final answer
   x = 81.48