Finding the Fourth Proportional to 78.82, 118.46 and 65.91

Step by Step Solution

1. Step 1: Write the proportion equation
   78.82 : 118.46 = 65.91 : x
2. Step 2: Convert to fraction form
   78.82/118.46 = 65.91/x
3. Step 3: Cross multiply
   78.82x = 118.46 × 65.91
4. Step 4: Simplify right side
   78.82x = 7,808.31
5. Step 5: Solve for x
   x = 7,808.31/78.82
6. Step 6: Final answer
   x = 99.06