Finding the Fourth Proportional to 127.31, 175.69 and 78.18

Step by Step Solution

1. Step 1: Write the proportion equation
   127.31 : 175.69 = 78.18 : x
2. Step 2: Convert to fraction form
   127.31/175.69 = 78.18/x
3. Step 3: Cross multiply
   127.31x = 175.69 × 78.18
4. Step 4: Simplify right side
   127.31x = 13,734.17
5. Step 5: Solve for x
   x = 13,734.17/127.31
6. Step 6: Final answer
   x = 107.88