Finding the Fourth Proportional to 109.32, 163.78 and 78.82

Step by Step Solution

1. Step 1: Write the proportion equation
   109.32 : 163.78 = 78.82 : x
2. Step 2: Convert to fraction form
   109.32/163.78 = 78.82/x
3. Step 3: Cross multiply
   109.32x = 163.78 × 78.82
4. Step 4: Simplify right side
   109.32x = 12,909.14
5. Step 5: Solve for x
   x = 12,909.14/109.32
6. Step 6: Final answer
   x = 118.09