Finding the Fourth Proportional to 72.63, 109.08 and 42.21

Step by Step Solution

1. Step 1: Write the proportion equation
   72.63 : 109.08 = 42.21 : x
2. Step 2: Convert to fraction form
   72.63/109.08 = 42.21/x
3. Step 3: Cross multiply
   72.63x = 109.08 × 42.21
4. Step 4: Simplify right side
   72.63x = 4,604.27
5. Step 5: Solve for x
   x = 4,604.27/72.63
6. Step 6: Final answer
   x = 63.39