Finding the Fourth Proportional to 82.58, 123.78 and 28.43

Step by Step Solution

1. Step 1: Write the proportion equation
   82.58 : 123.78 = 28.43 : x
2. Step 2: Convert to fraction form
   82.58/123.78 = 28.43/x
3. Step 3: Cross multiply
   82.58x = 123.78 × 28.43
4. Step 4: Simplify right side
   82.58x = 3,519.37
5. Step 5: Solve for x
   x = 3,519.37/82.58
6. Step 6: Final answer
   x = 42.62