Finding the Fourth Proportional to 78.68, 118.17 and 71.52

Step by Step Solution

1. Step 1: Write the proportion equation
   78.68 : 118.17 = 71.52 : x
2. Step 2: Convert to fraction form
   78.68/118.17 = 71.52/x
3. Step 3: Cross multiply
   78.68x = 118.17 × 71.52
4. Step 4: Simplify right side
   78.68x = 8,451.52
5. Step 5: Solve for x
   x = 8,451.52/78.68
6. Step 6: Final answer
   x = 107.42