Finding the Fourth Proportional to 124.55, 171.89 and 72.09

Step by Step Solution

1. Step 1: Write the proportion equation
   124.55 : 171.89 = 72.09 : x
2. Step 2: Convert to fraction form
   124.55/171.89 = 72.09/x
3. Step 3: Cross multiply
   124.55x = 171.89 × 72.09
4. Step 4: Simplify right side
   124.55x = 12,391.19
5. Step 5: Solve for x
   x = 12,391.19/124.55
6. Step 6: Final answer
   x = 99.49