Finding the Fourth Proportional to 82.42, 123.63 and 28.30

Step by Step Solution

1. Step 1: Write the proportion equation
   82.42 : 123.63 = 28.30 : x
2. Step 2: Convert to fraction form
   82.42/123.63 = 28.30/x
3. Step 3: Cross multiply
   82.42x = 123.63 × 28.30
4. Step 4: Simplify right side
   82.42x = 3,498.42
5. Step 5: Solve for x
   x = 3,498.42/82.42
6. Step 6: Final answer
   x = 42.45