Finding the Fourth Proportional to 90.27, 124.53 and 86.78

Step by Step Solution

1. Step 1: Write the proportion equation
   90.27 : 124.53 = 86.78 : x
2. Step 2: Convert to fraction form
   90.27/124.53 = 86.78/x
3. Step 3: Cross multiply
   90.27x = 124.53 × 86.78
4. Step 4: Simplify right side
   90.27x = 10,806.40
5. Step 5: Solve for x
   x = 10,806.40/90.27
6. Step 6: Final answer
   x = 119.71