Finding the Fourth Proportional to 90.72, 125.20 and 86.62

Step by Step Solution

1. Step 1: Write the proportion equation
   90.72 : 125.20 = 86.62 : x
2. Step 2: Convert to fraction form
   90.72/125.20 = 86.62/x
3. Step 3: Cross multiply
   90.72x = 125.20 × 86.62
4. Step 4: Simplify right side
   90.72x = 10,844.82
5. Step 5: Solve for x
   x = 10,844.82/90.72
6. Step 6: Final answer
   x = 119.54