Finding the Fourth Proportional to 82.68, 123.94 and 57.05

Step by Step Solution

1. Step 1: Write the proportion equation
   82.68 : 123.94 = 57.05 : x
2. Step 2: Convert to fraction form
   82.68/123.94 = 57.05/x
3. Step 3: Cross multiply
   82.68x = 123.94 × 57.05
4. Step 4: Simplify right side
   82.68x = 7,070.69
5. Step 5: Solve for x
   x = 7,070.69/82.68
6. Step 6: Final answer
   x = 85.52