Finding the Fourth Proportional to 72.77, 108.99 and 42.30

Step by Step Solution

1. Step 1: Write the proportion equation
   72.77 : 108.99 = 42.30 : x
2. Step 2: Convert to fraction form
   72.77/108.99 = 42.30/x
3. Step 3: Cross multiply
   72.77x = 108.99 × 42.30
4. Step 4: Simplify right side
   72.77x = 4,610.28
5. Step 5: Solve for x
   x = 4,610.28/72.77
6. Step 6: Final answer
   x = 63.36