Finding the Fourth Proportional to 72.59, 108.96 and 42.21

Step by Step Solution

1. Step 1: Write the proportion equation
   72.59 : 108.96 = 42.21 : x
2. Step 2: Convert to fraction form
   72.59/108.96 = 42.21/x
3. Step 3: Cross multiply
   72.59x = 108.96 × 42.21
4. Step 4: Simplify right side
   72.59x = 4,599.20
5. Step 5: Solve for x
   x = 4,599.20/72.59
6. Step 6: Final answer
   x = 63.36