Finding the Fourth Proportional to 82.49, 123.90 and 71.69

Step by Step Solution

1. Step 1: Write the proportion equation
   82.49 : 123.90 = 71.69 : x
2. Step 2: Convert to fraction form
   82.49/123.90 = 71.69/x
3. Step 3: Cross multiply
   82.49x = 123.90 × 71.69
4. Step 4: Simplify right side
   82.49x = 8,881.77
5. Step 5: Solve for x
   x = 8,881.77/82.49
6. Step 6: Final answer
   x = 107.68