Finding the Fourth Proportional to 127.69, 191.69 and 86.04

Step by Step Solution

1. Step 1: Write the proportion equation
   127.69 : 191.69 = 86.04 : x
2. Step 2: Convert to fraction form
   127.69/191.69 = 86.04/x
3. Step 3: Cross multiply
   127.69x = 191.69 × 86.04
4. Step 4: Simplify right side
   127.69x = 16,493.01
5. Step 5: Solve for x
   x = 16,493.01/127.69
6. Step 6: Final answer
   x = 129.16