Finding the Fourth Proportional to 90.21, 124.38 and 82.56

Step by Step Solution

1. Step 1: Write the proportion equation
   90.21 : 124.38 = 82.56 : x
2. Step 2: Convert to fraction form
   90.21/124.38 = 82.56/x
3. Step 3: Cross multiply
   90.21x = 124.38 × 82.56
4. Step 4: Simplify right side
   90.21x = 10,268.81
5. Step 5: Solve for x
   x = 10,268.81/90.21
6. Step 6: Final answer
   x = 113.83