Finding the Fourth Proportional to 90.33, 135.41 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   90.33 : 135.41 = 42.18 : x
2. Step 2: Convert to fraction form
   90.33/135.41 = 42.18/x
3. Step 3: Cross multiply
   90.33x = 135.41 × 42.18
4. Step 4: Simplify right side
   90.33x = 5,711.38
5. Step 5: Solve for x
   x = 5,711.38/90.33
6. Step 6: Final answer
   x = 63.23