Finding the Fourth Proportional to 78.76, 118.69 and 72.82

Step by Step Solution

1. Step 1: Write the proportion equation
   78.76 : 118.69 = 72.82 : x
2. Step 2: Convert to fraction form
   78.76/118.69 = 72.82/x
3. Step 3: Cross multiply
   78.76x = 118.69 × 72.82
4. Step 4: Simplify right side
   78.76x = 8,643.01
5. Step 5: Solve for x
   x = 8,643.01/78.76
6. Step 6: Final answer
   x = 109.74