Finding the Fourth Proportional to 90.67, 136.29 and 82.18

Step by Step Solution

1. Step 1: Write the proportion equation
   90.67 : 136.29 = 82.18 : x
2. Step 2: Convert to fraction form
   90.67/136.29 = 82.18/x
3. Step 3: Cross multiply
   90.67x = 136.29 × 82.18
4. Step 4: Simplify right side
   90.67x = 11,200.31
5. Step 5: Solve for x
   x = 11,200.31/90.67
6. Step 6: Final answer
   x = 123.53