Finding the Fourth Proportional to 83.07, 123.86 and 82.05

Step by Step Solution

1. Step 1: Write the proportion equation
   83.07 : 123.86 = 82.05 : x
2. Step 2: Convert to fraction form
   83.07/123.86 = 82.05/x
3. Step 3: Cross multiply
   83.07x = 123.86 × 82.05
4. Step 4: Simplify right side
   83.07x = 10,162.30
5. Step 5: Solve for x
   x = 10,162.30/83.07
6. Step 6: Final answer
   x = 122.34