Finding the Fourth Proportional to 127.48, 190.78 and 78.71

Step by Step Solution

1. Step 1: Write the proportion equation
   127.48 : 190.78 = 78.71 : x
2. Step 2: Convert to fraction form
   127.48/190.78 = 78.71/x
3. Step 3: Cross multiply
   127.48x = 190.78 × 78.71
4. Step 4: Simplify right side
   127.48x = 15,016.29
5. Step 5: Solve for x
   x = 15,016.29/127.48
6. Step 6: Final answer
   x = 117.79