Finding the Fourth Proportional to 109.72, 151.18 and 78.58

Step by Step Solution

1. Step 1: Write the proportion equation
   109.72 : 151.18 = 78.58 : x
2. Step 2: Convert to fraction form
   109.72/151.18 = 78.58/x
3. Step 3: Cross multiply
   109.72x = 151.18 × 78.58
4. Step 4: Simplify right side
   109.72x = 11,879.72
5. Step 5: Solve for x
   x = 11,879.72/109.72
6. Step 6: Final answer
   x = 108.27