Finding the Fourth Proportional to 127.77, 191.58 and 91.72

Step by Step Solution

1. Step 1: Write the proportion equation
   127.77 : 191.58 = 91.72 : x
2. Step 2: Convert to fraction form
   127.77/191.58 = 91.72/x
3. Step 3: Cross multiply
   127.77x = 191.58 × 91.72
4. Step 4: Simplify right side
   127.77x = 17,571.72
5. Step 5: Solve for x
   x = 17,571.72/127.77
6. Step 6: Final answer
   x = 137.53