Finding the Fourth Proportional to 82.68, 123.99 and 28.56

Step by Step Solution

1. Step 1: Write the proportion equation
   82.68 : 123.99 = 28.56 : x
2. Step 2: Convert to fraction form
   82.68/123.99 = 28.56/x
3. Step 3: Cross multiply
   82.68x = 123.99 × 28.56
4. Step 4: Simplify right side
   82.68x = 3,541.15
5. Step 5: Solve for x
   x = 3,541.15/82.68
6. Step 6: Final answer
   x = 42.83