Finding the Fourth Proportional to 72.45, 108.56 and 42.05

Step by Step Solution

1. Step 1: Write the proportion equation
   72.45 : 108.56 = 42.05 : x
2. Step 2: Convert to fraction form
   72.45/108.56 = 42.05/x
3. Step 3: Cross multiply
   72.45x = 108.56 × 42.05
4. Step 4: Simplify right side
   72.45x = 4,565.32
5. Step 5: Solve for x
   x = 4,565.32/72.45
6. Step 6: Final answer
   x = 63.01