Finding the Fourth Proportional to 82.17, 123.09 and 38.78

Step by Step Solution

1. Step 1: Write the proportion equation
   82.17 : 123.09 = 38.78 : x
2. Step 2: Convert to fraction form
   82.17/123.09 = 38.78/x
3. Step 3: Cross multiply
   82.17x = 123.09 × 38.78
4. Step 4: Simplify right side
   82.17x = 4,773.43
5. Step 5: Solve for x
   x = 4,773.43/82.17
6. Step 6: Final answer
   x = 58.09