Finding the Fourth Proportional to 89.71, 134.49 and 82.18

Step by Step Solution

1. Step 1: Write the proportion equation
   89.71 : 134.49 = 82.18 : x
2. Step 2: Convert to fraction form
   89.71/134.49 = 82.18/x
3. Step 3: Cross multiply
   89.71x = 134.49 × 82.18
4. Step 4: Simplify right side
   89.71x = 11,052.86
5. Step 5: Solve for x
   x = 11,052.86/89.71
6. Step 6: Final answer
   x = 123.21