Finding the Fourth Proportional to 109.82, 151.56 and 78.74

Step by Step Solution

1. Step 1: Write the proportion equation
   109.82 : 151.56 = 78.74 : x
2. Step 2: Convert to fraction form
   109.82/151.56 = 78.74/x
3. Step 3: Cross multiply
   109.82x = 151.56 × 78.74
4. Step 4: Simplify right side
   109.82x = 11,933.83
5. Step 5: Solve for x
   x = 11,933.83/109.82
6. Step 6: Final answer
   x = 108.67