Finding the Fourth Proportional to 90.16, 135.32 and 42.16

Step by Step Solution

1. Step 1: Write the proportion equation
   90.16 : 135.32 = 42.16 : x
2. Step 2: Convert to fraction form
   90.16/135.32 = 42.16/x
3. Step 3: Cross multiply
   90.16x = 135.32 × 42.16
4. Step 4: Simplify right side
   90.16x = 5,705.09
5. Step 5: Solve for x
   x = 5,705.09/90.16
6. Step 6: Final answer
   x = 63.28