Finding the Fourth Proportional to 82.17, 123.48 and 81.54

Step by Step Solution

1. Step 1: Write the proportion equation
   82.17 : 123.48 = 81.54 : x
2. Step 2: Convert to fraction form
   82.17/123.48 = 81.54/x
3. Step 3: Cross multiply
   82.17x = 123.48 × 81.54
4. Step 4: Simplify right side
   82.17x = 10,068.56
5. Step 5: Solve for x
   x = 10,068.56/82.17
6. Step 6: Final answer
   x = 122.53