Finding the Fourth Proportional to 121.50, 182.10 and 72.72

Step by Step Solution

1. Step 1: Write the proportion equation
   121.50 : 182.10 = 72.72 : x
2. Step 2: Convert to fraction form
   121.50/182.10 = 72.72/x
3. Step 3: Cross multiply
   121.50x = 182.10 × 72.72
4. Step 4: Simplify right side
   121.50x = 13,242.31
5. Step 5: Solve for x
   x = 13,242.31/121.50
6. Step 6: Final answer
   x = 108.99