Finding the Fourth Proportional to 82.42, 123.05 and 72.16

Step by Step Solution

1. Step 1: Write the proportion equation
   82.42 : 123.05 = 72.16 : x
2. Step 2: Convert to fraction form
   82.42/123.05 = 72.16/x
3. Step 3: Cross multiply
   82.42x = 123.05 × 72.16
4. Step 4: Simplify right side
   82.42x = 8,879.16
5. Step 5: Solve for x
   x = 8,879.16/82.42
6. Step 6: Final answer
   x = 107.73