Finding the Fourth Proportional to 82.17, 123.28 and 28.07

Step by Step Solution

1. Step 1: Write the proportion equation
   82.17 : 123.28 = 28.07 : x
2. Step 2: Convert to fraction form
   82.17/123.28 = 28.07/x
3. Step 3: Cross multiply
   82.17x = 123.28 × 28.07
4. Step 4: Simplify right side
   82.17x = 3,460.47
5. Step 5: Solve for x
   x = 3,460.47/82.17
6. Step 6: Final answer
   x = 42.11