Finding the Fourth Proportional to 72.53, 108.70 and 42.12

Step by Step Solution

1. Step 1: Write the proportion equation
   72.53 : 108.70 = 42.12 : x
2. Step 2: Convert to fraction form
   72.53/108.70 = 42.12/x
3. Step 3: Cross multiply
   72.53x = 108.70 × 42.12
4. Step 4: Simplify right side
   72.53x = 4,578.44
5. Step 5: Solve for x
   x = 4,578.44/72.53
6. Step 6: Final answer
   x = 63.12