Finding the Fourth Proportional to 123.55, 185.09 and 72.09

Step by Step Solution

1. Step 1: Write the proportion equation
   123.55 : 185.09 = 72.09 : x
2. Step 2: Convert to fraction form
   123.55/185.09 = 72.09/x
3. Step 3: Cross multiply
   123.55x = 185.09 × 72.09
4. Step 4: Simplify right side
   123.55x = 13,342.78
5. Step 5: Solve for x
   x = 13,342.78/123.55
6. Step 6: Final answer
   x = 107.99