Finding the Fourth Proportional to 119.82, 165.22 and 78.31

Step by Step Solution

1. Step 1: Write the proportion equation
   119.82 : 165.22 = 78.31 : x
2. Step 2: Convert to fraction form
   119.82/165.22 = 78.31/x
3. Step 3: Cross multiply
   119.82x = 165.22 × 78.31
4. Step 4: Simplify right side
   119.82x = 12,938.38
5. Step 5: Solve for x
   x = 12,938.38/119.82
6. Step 6: Final answer
   x = 107.98