Finding the Fourth Proportional to 72.72, 108.91 and 42.19

Step by Step Solution

1. Step 1: Write the proportion equation
   72.72 : 108.91 = 42.19 : x
2. Step 2: Convert to fraction form
   72.72/108.91 = 42.19/x
3. Step 3: Cross multiply
   72.72x = 108.91 × 42.19
4. Step 4: Simplify right side
   72.72x = 4,595.07
5. Step 5: Solve for x
   x = 4,595.07/72.72
6. Step 6: Final answer
   x = 63.19