Finding the Fourth Proportional to 82.42, 123.72 and 82.18

Step by Step Solution

1. Step 1: Write the proportion equation
   82.42 : 123.72 = 82.18 : x
2. Step 2: Convert to fraction form
   82.42/123.72 = 82.18/x
3. Step 3: Cross multiply
   82.42x = 123.72 × 82.18
4. Step 4: Simplify right side
   82.42x = 10,167.31
5. Step 5: Solve for x
   x = 10,167.31/82.42
6. Step 6: Final answer
   x = 123.36