Finding the Fourth Proportional to 82.39, 123.60 and 28.28

Step by Step Solution

1. Step 1: Write the proportion equation
   82.39 : 123.60 = 28.28 : x
2. Step 2: Convert to fraction form
   82.39/123.60 = 28.28/x
3. Step 3: Cross multiply
   82.39x = 123.60 × 28.28
4. Step 4: Simplify right side
   82.39x = 3,495.72
5. Step 5: Solve for x
   x = 3,495.72/82.39
6. Step 6: Final answer
   x = 42.43