Finding the Fourth Proportional to 90.17, 135.29 and 42.06

Step by Step Solution

1. Step 1: Write the proportion equation
   90.17 : 135.29 = 42.06 : x
2. Step 2: Convert to fraction form
   90.17/135.29 = 42.06/x
3. Step 3: Cross multiply
   90.17x = 135.29 × 42.06
4. Step 4: Simplify right side
   90.17x = 5,690.30
5. Step 5: Solve for x
   x = 5,690.30/90.17
6. Step 6: Final answer
   x = 63.11