Finding the Fourth Proportional to 78.69, 117.73 and 72.82

Step by Step Solution

1. Step 1: Write the proportion equation
   78.69 : 117.73 = 72.82 : x
2. Step 2: Convert to fraction form
   78.69/117.73 = 72.82/x
3. Step 3: Cross multiply
   78.69x = 117.73 × 72.82
4. Step 4: Simplify right side
   78.69x = 8,573.10
5. Step 5: Solve for x
   x = 8,573.10/78.69
6. Step 6: Final answer
   x = 108.95