Finding the Fourth Proportional to 78.68, 118.55 and 72.62

Step by Step Solution

1. Step 1: Write the proportion equation
   78.68 : 118.55 = 72.62 : x
2. Step 2: Convert to fraction form
   78.68/118.55 = 72.62/x
3. Step 3: Cross multiply
   78.68x = 118.55 × 72.62
4. Step 4: Simplify right side
   78.68x = 8,609.10
5. Step 5: Solve for x
   x = 8,609.10/78.68
6. Step 6: Final answer
   x = 109.42