Finding the Fourth Proportional to 83.22, 123.95 and 82.15

Step by Step Solution

1. Step 1: Write the proportion equation
   83.22 : 123.95 = 82.15 : x
2. Step 2: Convert to fraction form
   83.22/123.95 = 82.15/x
3. Step 3: Cross multiply
   83.22x = 123.95 × 82.15
4. Step 4: Simplify right side
   83.22x = 10,182.49
5. Step 5: Solve for x
   x = 10,182.49/83.22
6. Step 6: Final answer
   x = 122.36