Finding the Fourth Proportional to 82.65, 123.99 and 28.55

Step by Step Solution

1. Step 1: Write the proportion equation
   82.65 : 123.99 = 28.55 : x
2. Step 2: Convert to fraction form
   82.65/123.99 = 28.55/x
3. Step 3: Cross multiply
   82.65x = 123.99 × 28.55
4. Step 4: Simplify right side
   82.65x = 3,540.12
5. Step 5: Solve for x
   x = 3,540.12/82.65
6. Step 6: Final answer
   x = 42.83