Finding the Fourth Proportional to 82.56, 123.98 and 71.76

Step by Step Solution

1. Step 1: Write the proportion equation
   82.56 : 123.98 = 71.76 : x
2. Step 2: Convert to fraction form
   82.56/123.98 = 71.76/x
3. Step 3: Cross multiply
   82.56x = 123.98 × 71.76
4. Step 4: Simplify right side
   82.56x = 8,896.80
5. Step 5: Solve for x
   x = 8,896.80/82.56
6. Step 6: Final answer
   x = 107.76