Finding the Fourth Proportional to 123.50, 185.20 and 72.16

Step by Step Solution

1. Step 1: Write the proportion equation
   123.50 : 185.20 = 72.16 : x
2. Step 2: Convert to fraction form
   123.50/185.20 = 72.16/x
3. Step 3: Cross multiply
   123.50x = 185.20 × 72.16
4. Step 4: Simplify right side
   123.50x = 13,364.30
5. Step 5: Solve for x
   x = 13,364.30/123.50
6. Step 6: Final answer
   x = 108.21