Finding the Fourth Proportional to 123.60, 185.46 and 72.18

Step by Step Solution

1. Step 1: Write the proportion equation
   123.60 : 185.46 = 72.18 : x
2. Step 2: Convert to fraction form
   123.60/185.46 = 72.18/x
3. Step 3: Cross multiply
   123.60x = 185.46 × 72.18
4. Step 4: Simplify right side
   123.60x = 13,386.50
5. Step 5: Solve for x
   x = 13,386.50/123.60
6. Step 6: Final answer
   x = 108.31