Finding the Fourth Proportional to 124.72, 186.89 and 90.55

Step by Step Solution

1. Step 1: Write the proportion equation
   124.72 : 186.89 = 90.55 : x
2. Step 2: Convert to fraction form
   124.72/186.89 = 90.55/x
3. Step 3: Cross multiply
   124.72x = 186.89 × 90.55
4. Step 4: Simplify right side
   124.72x = 16,922.89
5. Step 5: Solve for x
   x = 16,922.89/124.72
6. Step 6: Final answer
   x = 135.69