Finding the Fourth Proportional to 72.59, 109.56 and 72.18

Step by Step Solution

1. Step 1: Write the proportion equation
   72.59 : 109.56 = 72.18 : x
2. Step 2: Convert to fraction form
   72.59/109.56 = 72.18/x
3. Step 3: Cross multiply
   72.59x = 109.56 × 72.18
4. Step 4: Simplify right side
   72.59x = 7,908.04
5. Step 5: Solve for x
   x = 7,908.04/72.59
6. Step 6: Final answer
   x = 108.95