Finding the Fourth Proportional to 82.86, 123.81 and 72.06

Step by Step Solution

1. Step 1: Write the proportion equation
   82.86 : 123.81 = 72.06 : x
2. Step 2: Convert to fraction form
   82.86/123.81 = 72.06/x
3. Step 3: Cross multiply
   82.86x = 123.81 × 72.06
4. Step 4: Simplify right side
   82.86x = 8,921.75
5. Step 5: Solve for x
   x = 8,921.75/82.86
6. Step 6: Final answer
   x = 107.67