Finding the Fourth Proportional to 82.49, 113.91 and 78.76

Step by Step Solution

1. Step 1: Write the proportion equation
   82.49 : 113.91 = 78.76 : x
2. Step 2: Convert to fraction form
   82.49/113.91 = 78.76/x
3. Step 3: Cross multiply
   82.49x = 113.91 × 78.76
4. Step 4: Simplify right side
   82.49x = 8,971.55
5. Step 5: Solve for x
   x = 8,971.55/82.49
6. Step 6: Final answer
   x = 108.76