Finding the Fourth Proportional to 72.68, 109.06 and 42.20

Step by Step Solution

1. Step 1: Write the proportion equation
   72.68 : 109.06 = 42.20 : x
2. Step 2: Convert to fraction form
   72.68/109.06 = 42.20/x
3. Step 3: Cross multiply
   72.68x = 109.06 × 42.20
4. Step 4: Simplify right side
   72.68x = 4,602.33
5. Step 5: Solve for x
   x = 4,602.33/72.68
6. Step 6: Final answer
   x = 63.32