Finding the Fourth Proportional to 72.60, 108.81 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   72.60 : 108.81 = 42.18 : x
2. Step 2: Convert to fraction form
   72.60/108.81 = 42.18/x
3. Step 3: Cross multiply
   72.60x = 108.81 × 42.18
4. Step 4: Simplify right side
   72.60x = 4,589.61
5. Step 5: Solve for x
   x = 4,589.61/72.60
6. Step 6: Final answer
   x = 63.22