Finding the Fourth Proportional to 72.68, 108.84 and 42.15

Step by Step Solution

1. Step 1: Write the proportion equation
   72.68 : 108.84 = 42.15 : x
2. Step 2: Convert to fraction form
   72.68/108.84 = 42.15/x
3. Step 3: Cross multiply
   72.68x = 108.84 × 42.15
4. Step 4: Simplify right side
   72.68x = 4,588.05
5. Step 5: Solve for x
   x = 4,588.05/72.68
6. Step 6: Final answer
   x = 63.13